I would very much support a level sync on demand to a preferred level by the party leader, counting trusts as applicable party members to engage sync (They apply to everything else after all)

Maybe to some people this game is about 99 content. And that's true for those who feel that way, but there's a lot of people who want to go back to old content or people doing that for the first time that don't want to facepalm every mob in the zone in 2 seconds or less, and even people who want to stay in vana'diel capped at 75.

I'm one of those people who very enjoy older content, as is my partner. Despite having a lv 99 for like a year on at least one character, and having 99 on my new one for about 6 months, my partner and i only this last sunday went through adoulin collecting KI's for revies (Even though we've had adoulin since january of last year). We still do sky, sea, older missions and battlefields like ANNM's quite often, mostly just use adoulin atm to get merits quickly, though we are looking at doing skirmishes to get better armour to hit high level mobs, but that's mostly a side job.

When I was re-doing promathia missions on cymo, I used under leveled equipment and sync'd with my alt to use trust npc's as much as I could to advance, because on my previous character, we had like, zero trouble doing it all at 99 so much so that we basically wiped promathia so fast we felt incredibly let down. When I re-made my character I set out to do the missions at a better pace and to get more challenge out of it. If we could level sync on demand to specific levels even in mission/quest/etcc battlefields, it would be really amazing and i think would make a lot of people happy. Esp those who keep asking for a lv 75 server. Sure, aby, adoulin content would still be there, but they could more or less do the same thing by just syncing through all of it.

Kills 2 birds with 1 stone, and helps the player base a lot in many ways, old and new.

Sounds like a win win to me.