In my mind, aside from the thiaminase issues, I would also be somewhat concerned about the risk of introducing pathogens and parasites, especially the intestinal worm types that may be present in wild caught fish. While those things may or may not have immediate impact and your snake or snakes, and they won't likely die right after you feed them, you may need to weigh those risks for your individual situation, and while those risks may or may not be immediately life threatening to a snake, it my might not be worth the long term risks to a relatively large collection. Not to make you paranoid or rain on the idea, because how big a risk? or how real a threat? or what are your odds of a snake getting a disease or parasite and parishing or spreading that around to other snakes in a collection? I have no idea what that real data is, just my 2 cents and food for thought. Of course snakes in the wild are subject to those same health risks when eating wild fish, but in captivity the entire enviromental conditions and formulas changes, including resistance, and you basically have control of the enviroment and risks to an extent, not nature.
By the way, I absolutely love to fish, congrats on the white bass day, and the thought of feeding fish that I catch has crossed my mind too, I mostly catch crappies, walleye and catfish around here, but I am just not willing to risk it with my collection, I have enough to worry about without another variable, but thats just me and my oppinion.