I've personally submitted KYC, BetPanda didn't ask for it initially, but I preferred to be done with it as it would ask me eventually.
You did the right thing, imo.
If you intend to play at a casino for long time and make huge deposits/withdrawals or small ones but on a regular basis then it wud be better to complete kyc from the beginning, even if they don’t ask fo it, and be sure that you pass it sccessfuly and that everything is fine.
This way you will be sure you won’t face any implesant surprizes in the future.