Maxwell wrote:

What is the general consensus of the group? Flaps up or down, after
touchdown on a soft field landing?

what does the POH say? if it says anything about it, that's what you
do; if the POH doesn't say anything, what does the FAA says, i.e.,
chapter 8.17 of the Airplane Flying Handbook (FAA-H-8083-3A)

In either case, politely remind the instructor that this is a *soft*
landing and not a *short* landing so effective braking is not an issue
(on a real soft field, slowing down will be taken care of by the field,
don't worry about it :-)

--Sylvain