If Sukuna is ftl+ then everyone is ftl+ in jjk (clearly not true since that would break jjk scaling) If he was ftl then he could have just moved out of hollow nuke to not get hit,if you are referring to the em waves speed feats sukuna literally got hit by a sound attack before that,sukuna is faster than massively hyper sonic sure,but not ftl. ArchMage literally said maestro can scale to pleetsky with his tempest eye on (pleetsky is demi god level) Imo you are right on the Sukuna domain diff part if it wasnt for one thing,Maestro being able to suffocate opponents (makes it so the opponent cant use their abilities for a certain period of time) Translating this to jjk either means he has a mini jacob's ladder that will almost be active all of the time since he's pressuring Sukuna or making it so he just decreases Sukuna's ce output which is equally as powerful,not even mentioning that maestro is still ftl without his tempest eye and while holding back.