Thanks PB. I'll be using some beefier SiC Schottky rectifier diodes rated for 42A non-repetitive surge current, and for 21A of repetitive surge current: FFSP05120A. I'm more concerned about the life of the doubler caps. I'll be using some long life Rubycon BXW 220u 400V caps. Datasheet attached. The datasheet doesn't mention max instantaneous ripple current -- maybe that doesn't exist? (But I thought I read about that somewhere when I was selecting caps a few months ago). According to PSUD, peak current drops to below 2A after 1500 ms, so maybe I don't need to worry about the doubler caps heating up. Dunno. I'm totally ignorant here.
Good point about voltage sag @ 18A draw. PSUD shows a modest sag, but nowhere near as low as I would expect based on my limited experience.
Thanks for the suggestion of the CL90. Is there a particular brand you would recommend? I may install it just out of an abudance of caution.
cheers and many thanks, Derek