I think there are two separate issues at play here, and potentially some confusion. Issues 1, play to the rules, and put in your card according to WHS. This is being done in your roll ups, on at least one occasion per month. All good, and as per your post.Though surely the rollup will simply work out stableford or net score - they won’t adjust the players gross and that’s what would be input for WHS.
The problem, according to EG, is the organiser then works their magic and manipulates the scores further by taking into account the roll up h/c. This is the point under discussion and is the problematic part.
My question to D-S, which I don't expect him to be able to answer so it was more about floating it, is are people able to continue to play in the roll up if they don't want the magic handicap to kick in and the roll up h/c to work? You don't want your h/c removed but the roll up insists on their h/c system. The roll up either has to full comply or those taking part will only be those who accept the withdrawl of official h/c. There is no half way house. (again, the likelihood of this happening does not sound great but it is what they have suggested to D-S, quite emphatically)