The fix for this is simple: ANY access of the game at all ends the vacation. Open the site at all? Open the app with an activate internet connection? Boom, clearly you're able to play, vacation over. Then there's no ambiguity about how the feature should work and no need for complex lists.
The great solution from the messiah, like the bible too bloody wrong and here's why...
This solution only works if you play automatic distribution templates that have no strategic value for the most part and would be classed as brainless play.. Brainless play can easily be done in one sitting at the end of vacation and you have that extra hour to do it all and tadah you're happy as a dog.
Since you have made this game to be competitive and you have multiple formats promoting competitive play (1v1 2v2 3v3 ladders), You're going to have players who are competitive on your site who will need to take their time playing on the game. This is why I'm born on your site. You brought me here daddy and I'm your little happy accident causing you a headache.
For someone like me, I play team games and I generally play to a high level cause I take my time playing. Statistics wise I'm up there to a relatively top enough level for team games. So for me to do team games in one sitting is impossible, I would have to sacrifice the quality of moves since I can't co-ordinate with team-mates. The 1v1 games it's possible to do this but team games, don't even start. Have you played team games Fizzer? If so, you should understand where I'm coming at.
It's impossible to abuse vacations like for me to "abuse a vacation" is to gain an advantage. I don't think that's possible and if it is that's a bloody rare situation whereby stalling all your games is going to work. You leave ladders automatically to activate vacations and you can't vacation individual games, it's either you vacation all games or not. So where's the area for abusing the feature for an advantage?
I trust the players when they vacation have very valid reasons for vacationing and it's none of my business what for.. It could be death to a family to not feeling mentally up for it, hell even if they wanted to take a shit in the toilet they can go for it. Everyone has a good intention for vacationing if they feel they can't commit to their games for whatever reason and I think that's grounds for a vacation and not to be labeled as "abuse".
Edited 7/17/2019 23:14:02