I suggest
https://duckdice.io/ I'm not sure with
https://bustadice.com/ but they are a good provably fair game provider. May I ask why don't you just stick with the Wolf.bet? do you have any problems using it or anything that stops you from playing on that site?
Didn't duckdice had some issues before? I haven't seen any issue with bustadice before so I am more inclined to trust them more than the other that has an issue. Even if they've solved it, the trust won't be the same.
Bustadice is good but as far as I know, there's not flash bets on this platform though they have auto bet but not a flash one that OP is looking for. If I were to OP, I'll stick to Wolfbet since that's also a good site and its hard now to trust another gambling site especially if you are new to it. I've tried flash bets before on Wolfbet and it's really working fine.