Why any provider would accept a personal check from a client unless they’ve enjoyed a long relationship is baffling. The protocol on first meeting is to leave the fee in full sight. 90% of providers will find this to be quite acceptable.
As for the flakes, the providers I know are fairly adept at discerning the flakes and blocking them. I know a number who have never been burned. Discernment aside, sociopaths constitute 4% of the US population, so encountering them, as has been reported, is, sadly, the cost of business.