Hello,
today I entered an expert roulette (Brayflox hard popped) just to see the vote to abandon message pop a bit after the 2nd boss died.
I refused but the dungeon ended anyway. After a bit of research I found out that the other 3 people were from the same server (Cerberus), 2 of which were in the same FC. Probably it was a party finder trying to abuse the duty finder for myth farm.

Anyway…
tl;dr
As a possible solution, would it be possible to increase the 15min timer before the vote to abandon is available by something like 5 minutes everytime a boss is killed? So if after a boss 3 minutes are left on the timer, it would be increased to 8 minutes.
If the party is going well (if the bosses are being killed, it means that it's not going bad) the vote to abandon will be hardly needed and increasing the timer could prevent those people from abusing it.

Thank you.