I think the OP makes an excellent point about using digital images for instruction purposes, assuming of course that the groups in question actually mean that he'd have to do what he assumes he'd have to, in order to post instructions with pictures
If I need knowledge to further my use and enjoyment of analogue cameras, processing etc which is the example he gave then why have rules that frustrates this?
The OP might not then bother to do what he thinks he is forced to and the only sufferers are those of us who need that knowledge that the OP possesses.
I was a recipient of the very instruction he mentions, namely the conversion of a 220 P645N insert to a 120 insert.
Thanks for that GRHazelton.
What might make sense is a rule that says that in the galleries all scans should be from prints and not from neg scans which like the instruction example the OP gives, should be confined to issues about neg problems such those of the "what went wrong here?" type