So far the worst case of gating I've run into was not the story progress, but SP and Arbitrations (and their respective mods) gated behind the FULL star chart clear. We tried to play SP circuit for giggles with one of our friends who's extremely behind us, game said "#*!% you lol, go clear every map node", and that was it.
The problem with gating isn't the quests. It's specifically Zariman, its nodes being counted towards starchart unlocking, and it being locked behind New war for... for what reason exactly? They aren't connected. With the way Zariman is introduced, it can just be plugged literally anywhere.
At the very least, make Zariman NOT count towards basic chart progression. That alone will unlock a big chunk of the game for players who don't want to deal with story just yet. Better yet, find a way to not lock Zariman and the whole upcoming Void arc behind New war, because that particular quest is 90% of a problem with quest gating in the game. Maybe rework New war, IDK.