To me the problem is that there are no middle ground between allowing maximum vacation time and not allowing any vacation time. That is why I think it should be integrated into the time control. Give those that needs a lot of vacation time the option to do so, while also giving those that needs less the option for that too.
Trying to find a middle ground by changing the cap will not solve the problem. A 30 day break is more substantial in 1 day/move games than in 14 days/move games.
Even legitimate vacations can slow down tournaments a lot.
It will be harder to track vacation for each game, but I think it is worth it. The UI mainly needs to tell the player the vacation time they have available which are the lowest.
For me, the single biggest problem with vacation time is the inequality in time between premium and non-premium accounts.
If it were suggested that premium acct were to be allowed an increment but non premium accounts weren’t in live games, there would be an uproar. It’s not right to give some players more vacation time than others just because they pay more, have a higher rating, or work here.
chess.com needs to make the playing field equal for all. It should do so in a way that is not onerous to premium accounts, which means increasing vacation time for many non-premium players, but it doesn’t need to be 2 months per year.