Just now starting the final sector of the Hero Mode campaign myself. Took my sweet time and picked up the scroll and sardine-thingy for each stage. Now if I have to redo any stages I can just speed run through them.
And while taking a break from that I played around with my empty weapon inventory consisting of the Splattershot Jr., Splat Charger, and Inkbrush

. Turns out that when you activate the Sting Ray you
cannot super jump at anytime, or even pre-load a super jump, until your meter is depleted. However, you can super jump while wearing Ink Armor and keep it for its duration. You can also activate Ink Armor before landing, but you're still bound to the charge up time before it fully activates. And Splashdown can be pre-loaded as early as immediately after picking your destination. Instead of the sudden midair pause before slamming down she'll just come roaring in without pause. Not sure how much time that shaves off, if at all.