clock run in classic 20+ minutes, possible solutions.

what happened.

I was facing an opponent playing quickly the grob. After some development moves he grabbed a pawn on c6 checking me and i retreated to safety on f7. while he was doing his queen side moves i grabbed material and his best defender was my pawn on e7. Stockfish had me on +9. Next move he made a mouse slip he wanted to play rook g8 but went to f8. +9 totally won so no mercy and i grabbed the rook with my e7 pawn. 1 move later i had mate in 3 whatever he did.
Next he lets his clock run for 20+ minutes!!

what can i do at that moment.
- I was cooking atm so i had something to do but i really hate this. had to look every 2 min if there was any movement.
option 1: Browse my computer. Leave the screen he can claim i left the game and win.
option 2: just let the clock run out. He can resign and i am paired up with a 1500 and loose tons of rating. (this happened before)
option 3: Wait it out for 20 fff minutes while every 2 min orso i have to look at the computer.

Look at his punishment.
He gets a warning for letting the clock run out.
20 seconds in bullet vs 20 minutes in classic gives the same warning. 20 min in classic should be a real big punishment.
I had that warning 2 sometime in bullet or blitz while i was franticly thinking how to mate my opponent. (of topic: had the lost on purpose warning in atomic and i sure did not loose on purpose.)

Possible solutions.
Max thinking time 5 min. (say 25% of initial thinking time)

Warning time run out punishment according to how many minutes you let your clock run down.

Maybe he was also cooking and his kitchen caught fire. But yeah, probably offenders or repeat offenders should have to talk with moderators when they've greatly inconvenienced their opponents like that.

It's a real problem, it's unbelievable that anyone except a child would do this, but it keeps happening
That's 1 reason I play 10+0, it limits their ability to do this
I agree with you, I would like to see harsher punishments, the only problem is to not falsely accuse someone, I played someone when I had a very bad connection, continually losing and then regaining the connection, they called me a cheater, thought I was disconnecting and using a computer or something, I was very upset and resigned on the spot
When this happens make sure to block them, so that you never play them again (except possibly in a tournament)
It is theoretically possible that there is a good reason for them to leave and not resign, but the timing is incredibly suspicious, they always do it after they drop a piece, they never do it after delivering a check

Also, with respect to them having a good reason for leaving and not resigning (resigning takes a second), if you look up their previous games you can see that it is consistent behaviour for them, it is not a one-off, so the site should be able to pick up this pattern and do something about such individuals