Okay, this one actually works in favour of the players (and I benefited a couple of times from it), but I thought, I might bring it up still:
Your delve tokens are reset to three, when you open the daily reset screen. They do not reset at the daily reset time.
You can start a (non-event) delve with expired delve tokens hours after the daily reset, as long as you do not exit to the world map, but stay in the kingdom.
Hello!
I sent this through to the team to investigate further! Thanks for sharing this report 
Jeto (she/they) - Support Human 