Hallo Rob,

'The only place I ever seen caps across the rectifier diodes in the last 25 years is in high voltage esoteric valve/tube audio equipment..'

I have had a short look into my archive and found the following devices indeed having caps accross rectifier diodes:

Albs Ram-4
Albs Pam-9
Albs Snt-12
Burmester 909
Elac 3401T
Grundig ST9000
Grundig T907
Grundig T9000
Grundig W6232
JR Transrotor Oyster
JVC XDZ505
Kenwood KA-880SD
Lindemann Amp3
Philips FT990
Philips V7001
Proceed Pre
Quintessence Crescendo
Rotel RC980 BX
Technics SVDA10
Technics SLPG400A
Yamaha CDX1100
Yamaha CDX5000

And there are dozens of others I have seen in the past.

Kai