Rebonjour:
CAP ratings: Used low ESR high current film caps in 1970s, like TRW. Mylar and polypropylene film caps with special terminations : AMP connector to all of the foil end layers.
WIMA stacked foil polypropylene , MKP4 for pulse application. AM unsure continuous RMS current at high freq.
https://www.mouser.com/datasheet/2/440/e_WIMA_MKP_4-1139861.pdfRE "free advice for his day job, which is the commercial design and production of power supplies."
I imagined ALL are welcome to EEVblog, to ask for advise regardless of their goal or position: Beginner, hobbyist/DIY, or OEM/professional.
Often a professional who seeks assistance has complex, rare and interesting problems and well framed questions.
Why not volunteer ones experience if it can help out a fellow engineer or technician?
CHEER UP!
Have an absolutely fantastic day!
Jon