How about when a person bets on a guy, but there's no counter and the person he bet on loses, then the winner takes the tc.

They do take some but it's not enough. I sunk 8100TC from a bet. I put in 9000TC and the person dq'd on the next frame (unexpectedly) and the winner only got 900TC. I know you are trying to sink TC but please consider this.

For example : I bet 10000 on A, but A loses to B. There were no counters against me, so normally my 9000 tc would sink, but if we add my idea to tb, then B would get all the tc I bet

This would make sense. The thing is, as said before, they want to sink TC.

But, considering the bet amount, it would be a great idea to implement in betting servers.

I don't bet, so my opinion really might not be valuable. I think that the TC percent should be configurable, but the default percent should be higher. Like, instead of 10%, make it 50-70% but have the option to be able to change it? Maybe that's still too much considering they're trying to sink TC.

Unsupported. TC needs to sink and this would also possibly cause more bet rigs

TC has to be sinked.
People shall bet at their own risk though. If you want to get the profit from the bet that's against you, do a self-bet.

Unsupported.