Are your "flat feet," and not age-related loss of fatty padding tissue, the issue? I do a lot of walking and some cycling and jogging, and I am in a lot of pain if I do not have decent cushioning gel inserts in my shoes, even the lightweight slip-ons I wear indoors. (Living on a western-style concrete slab instead of a raised foundation doesn't help.
)
I wonder if good old school touring platform pedals would help, although the ones you show should function similarly.
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"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069