Jon, have found these particular converters (as in post 1) somewhat flaky, manged to destroy two Massoth M decoders when used via the Function Outputs, they have been fine when connected via DEK+ & GND, I'd err on the side of caution and would if I ever used them again for regulating a Function Output would certainly fit a Schottky Diode.
The description for the newer versions has changed, they may well behave better, but on past experiences with Function Outputs I think I'd still fit a diode.
As Brucie would say in this game Go Lower!
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