Not my kind of thing, but your probably right if they fail on their own mashing the heck out of them cant be good.
Once I've tested some caps with it, job done, sorted.
I have an olde fashionde lopty, from an itt set, the one that converted pal to ntsc or something like that, anyway it doesnt have a rectifier, for a completed nicer version I'll do something with that and a stack of diodes.
I ha d wondered about not having a rect, flyback topolgy as you know can be arranged to produce lower forward volts at the secondary, and much higher reverse during flyback, this would average out on a cap, but methinks the amount of current to reverse the polarity due to reactance would probably blow something up.