gloss finishes

yep. you can use 0000 steel wool. swirl the pad and never go in one direction.
the results will look like you took steel wool to the surface

you could over spray the gloss finish with a satin spray, like Deft.
but there could be the risk of incompatibility of finish and your coating could flake off at some point in the future.
steel wool before satin spraying could help by creating a 'toothier 'surface for more 'bite' with the overspray.

compatible finishes have the ability to 'burn in', hus making a better bond.

the thought of you altering a nice gloss finish, however, kind of makes me ill.
what a nice opportunity to get another guitar. :)

well it's not really an idea i plan on doing anytime soon, i was just asking out of curiosity.

i had a gloss and a matte guitar next to each other and i was idly wondering if i could go from one to the other. i know it's possible to make a semi-gloss into a fuller gloss with some buffing and whatnot, i was just curious if it worked in the reverse

Usually when applying a film finish to wood, IMO, the best approach is to use gloss finish and then rub it down with something like 0000 steel wool wetted with kerosene so it's a bit softer shine. I'd be reluctant to do that to an already nicely finished shiny guitar, though. Semigloss finishes are a shortcut to the proper hand rubbing.

I did buy my son a Fender Highway One Strat that had been buffed to a nice soft gloss by the store personnel. I think it's much prettier than the original matte finish.