Thank you for the feedback!
The troops give the same XP and Gold to ensure that the player hits max level and score exactly if they exhaust all floors of encounters, but I get that it feels unsatisfying. I could alter how it picks encounters to cover that and have varying xp. The encounter limit is managed by a plug-in I wrote.
Accidentally triggering the final boss is an issue everyone seems to have had, I agree that it should at least have a warning to allow the player to finish their exploration.