I love theorycrafting about this stuff, perfect time for me to hop in here
personally, I think there are a multitude of weapons that you can use decently well to round out a support player's pool. main ones of course are zap 85 and nsplash, but other than those you definitely have options, but they all require quite a bit of skill/weapon knowledge to make work compared to zap/nsplash
wiper deco is a perfect example of one of these, however you need to unlearn your walk-and-shoot syndrome with this weapon. swimming in between every one/two horizontal slashes, as well as using vertical slashes to open up a fight, will be your main playstyle, since you lack torpedo with it. in return, you get beakons and missiles, which when used together can make for a very unique playstyle. using your body to distract on a flank, then jumping out to your beakon to safety, placing a beakon down again, and repeating is a recipe for success. missiles should always be followed up on as well, since your advantage state is right after you fire your missiles. try not to spam missiles with this weapon, no missile weapon is effective at spamming missiles thanks to the cooldown nerf, but wiper deco especially so
(TIP: you can see enemies with missiles locked onto them by a teammate through walls, but the effect is very faint, so if you run this in a comp setting your teammates should learn this)
vanilla jr is another great option, as said above. majority of players use it for double bomb spam, however I think the more optimal playstyle would be using one/two subs ink recovery along with last ditch effort, as well as a little bit of sub saver, so you can throw double bomb when points tick down, while having more bombs per match thanks to the gradual ink recovery boost. it is a paint behemoth, and throwing bombs at teammates that are fighting will help them tremendously. throwing a bomb before popping bubbler, then another bomb, is always a tried-and-true comp. try to use bubbler to paint aggressively in zones, or as a temporary shield for you or your team to cross perilous terrain easily (the ramp/tc right flank on inkblot, rainmaker checkpoints, etc)
flingza is in an awkward spot at the moment, since the meta is very fast for it. however, I think it can still get very good value if you know how to play it. as a flingza, my tip would be to pick your spots. you can paint very well and from behind cover for missiles, however you also can use ninja squid to swim up to someone and dunk on them if they overextend, similar to vroller. your retake is definitely rough if you don't capitalize on your missile displacement though, and flingza has a harder time at doing that. in return, it paints much more readily than wiper deco, and it is a menace when in control (like all rollers). make sure to place mines down as well in front of you/on common retake pathways, so if someone tries to rush you, the mine will help weaken them for your vertical flick
for less-picked but still very strong options (at least in my opinion, and have been seeing some results in japan), we have annaki nova, sorella undercover, zink mini, and dread wringer. these weapons more fill a niche, but are still fairly strong weapons when played to their strengths
annaki nova is mainly played for inkjet spam, so if you want to use this weapon you NEED to be good with inkjet. however, if you are good with inkjet, this weapon gets more inkjets than ballpoint thanks to it being gear independent. this allows for it to run more special charge than the regular ballpoint, as well as it being more mobile than a ballpoint. you need to learn the paint tech with annaki nova to properly paint with it, since the weapon's paint droplets are very weak, but with paint tech it paints a fair bit. your main game plan with this is similar to flingza but sacrificing a threatening one-shot on overextension for mobility: paint the map and farm for special; if someone rushes you, place a mine and back up, outranging the enemy and baiting them into your mine. if a mine explodes, your main weapon turns into a three-shot, and you have a deceptively long range, so you can easily kite the populer short-range weapons like vshot, n-zap, and vsplash. you'll most likely struggle against squeezers though, so be careful of them. as I said before, you NEED to be good with inkjet, so if you pick this up, practice your flick directs against both stationary and moving targets
sorella undercover can be very rough to play, since it takes three shots ideally to kill. however, it is a weapon that can win any 1v1 if it sets it up properly, thanks to both torpedo and its shield. if you throw a torpedo into the air or through/behind the enemy, then deploy your shield, you can very easily finish off enemies in a 1v1 since they eiter have to shoot the torpedo, or your shield. it also paints a lot, and every kill or assist regenerates its shield, which you can use to your advantage. one thing you can do, if you're more confident, is using your inkling hp as a sort of sponge before your shield activates, but that's often very risky and I'd advise against it. the only downside to this weapon is the special being incredibly weak (as well as banned in some tournaments still), but if you want to push it it's definitely possible
zink mini is hella underrated, and such a fun weapon. it struggles on retake, once again, but with the bubble pfs buff as well as the ink efficiency buff, it feels really nice. this weapon is very gear-dependent, so I'd recommend a minimum of 1 main 6 subs of run speed, as well as 3 subs of ink resistance. the way you play the weapon is to play it similar to a vshot with more range and slower velocity: charge up halfway (one circle), release a bit while strafing fully left/right, then before your charge is gone swim (most likely in the opposite directon) to reposition in the firefight. this weapon paints a lot, as well as having very decent range for the weapon. you need to get used to guessing where enemies will go, though, since this weapon has VERY slow bullet velocity. if you predict properly, you can easily paint in front of them and finish them off fully. for toxic mist, you can use them very aggressively with this weapon, throwing it on top of someone/behind someone to prevent them from running away, as well as generally being very mobile as a splatling
dread wringer is probably the best reefslider weapon, as well as being a strong frontline weapon that can also paint very well as a supportive option. I'd recommend picking up this weapon over tri nouveau mainly for the fact that this main weapon paints much more reliably than the tri main weapon, as well as having a longer safe painting range. tri nouveau relies a lot on its fizzy bomb to get into good positions, so it feels more like a slayer weapon that has supportive tendencies, than the other way around. dread wringer is a menace in zones, you can immediately cap zone with either reefslider alone or reefslider + suction bomb, as well as finish off weak enemies with one slosh. it may struggle in other modes (I can see it in rainmaker for both shield pop + desync glitches you can get in rainmaker, but that's very jank), however it definitely shines in zones
there are a couple of weapons I'd like to leave as a footnote: reef-lux deco and both h-3s. these are weaker weapons, as well as being very hard, so they aren't generally worth it. however, if you are very good at aiming with these weapons, you can do very well with these. I would recommend watching
atobaru,
wami, and
relreel on openrec/youtube live for these weapons
if you need any jp players to watch, feel free to dm me and I'll do my best to find them
