It is my opinion that frontline should just be replaced altogether with a different large scale PVP mode just like CC replaced The Feast.
I don’t hate frontline or anything, it’s nice casual roulette content to me, but it’s undeniable than the current PVP system is designed primarily for smaller scale skirmishes rather than huge groups of players squishing into each other (you could say this about old frontline too tbh, the mode has always had issues) The LBs and job design lead to cheesy synergy and strategies in large scale settings. The team that is able to group up the best and target one enemy at a time the best generally wins. If you are the one unlucky enough to be targeted in a bit team fight it’s over for you usually as you get melted in two seconds. This leads to cautious play where good players learn to never overextend as getting to close any enemies is basically instant deaths. That’s why melee jobs had to get ridiculous buffs in frontline in order to even be viable which leads to another problem where they are annoyingly tanky in more normal circumstances, and that only leads to ranged classes being further targeted by groups as the easy and squishy players for kills/points. There are also other issues with objectives like spawn RNG/etc that have already been discussed many times before.
With that rant out of the way, I think you can still have a large scale PVP game mode but focus it more on smaller skirmishes somehow since that is clearly what the current system is designed around. Doing this is a large open map would be tricky, but my proposal is an elimination/battle royale like system where you have multiple teams battling at the same time. Rather than the chaos and jank of 40 players in one area, you have smaller teams fighting each other concurrently. If your team wins a quick objective or even just wipes the other team, they move on to the next battle. This can also give the devs space to experiment with other objective types other than push the crystal and make this mode have more variety than CC. I am almost thinking of fall guys, but more like a tournament bracket. You could also do 10v10 or something instead of 5v5, which is still bigger than CC but not the craziness of frontline mosh pits.
It would need more fleshing out but I hope people can get the general idea of this. Maybe it could be something like this in practice: You get assigned to a team and get matched with another team and it’s a team death match setup where the first team to wipe is eliminated (or maybe there’s a limited res pool). Then you move on to the next round and now it’s a capture the point thing where you have like one to three points the teams are fighting to get the most uptime holding/downloading/etc. You move on and now there’s a challenge where you you have to gather coins/crystals/etc and you drop them upon death or etc (wasn’t the feast kind of like this?). Eventually you reach a final round which could be its own special challenge or maybe this could be a good spot for the classic TDM format.