Very similar to what a proper crime and punishment system would provide?
Given Frontiers reticence to provide a C&P to the game how likely do you think they would be willing to play constant hall monitor to a pve mode.
Yes and no. For some players it will be part yes/no, for some all yes, and for some like me - still all no.
2nd group - definitely sure that for some who currently play in Mobius, and would like open-pve, if such a thing as a truly 'good' C&P system existed, I believe they would move back to Open and see no need for Mobius and/or open-pve mode.
3rd group - no matter how good the C&P system is, the bottom line is that it will always be 'you can still do the crime' and then you'll face the 'punishment'. For many griefers, the joy of ruining someone's day will always be worth whatever the punishment - however horrendous and lop sided it may be to punish the griefer. So for many players, it doesn't matter how good the C&P system is if the crime part is still doable first.
Take Lineage 2 back when I played (years ago, no idea current state) - the murder penalty was so large you can be killed at will by anyone, and drop to the ground your own player loot / equipped gear that may have taken months to years of play to accumulate (very powerful weapons you need to craft, armor, etc). For just walking up and ganking someone, that griefer would turn red, be flagged as open loot piñata for anyone/everyone, and drop what in that game is a huge reward.
There was no 'sidewinder' kills in L2 back then, a griefer needed better arsenal than the avg player to kill them, so what they dropped was always worth taking. And yet hordes of griefers still existed, because it was a crime-then-punishment system, not immune-from-crime.
Re: FD reticence and hall monitor - can't read their minds but you asked my opinion so I'll give just that - an opinion, not saying I know as fact --> I believe the reason FD talks amongst themselves and decides 'we can wait on doing a pve mode' come s down to one single conclusion - 'well, they already have Mobius and that's a good enough Band-Aid for now'
If Mobius didn't exist, I think we'd have a pve mode already. Since it does, it allows FD to ignore or delay an actual pve mode. I've said it in a prior reply on this megathread somewhere - if it weren't for two filled to capacity Mobius groups already existing as partial relief valves, this balloon would have burst long ago.
Given the constant, steady growth of Mobius, whether it represents a majority or minority, reasonable people ought to be able to agree it is a pretty solid chunk of the player base, including obviously the many who play open but don't know about Mobius (just read the Mobius forums if you have access to it, read how many players join and first thing they say is 'omg, played ED for XX time and didn't even know about Mobius till now'.
So yes, I believe a proper C&P system will help for some, but in essence be another band aid for others. I don't think it will absolve the need for a true immunity mode, aka open-pve, for enough players that FD won't inevitably have to create that mode. Contentious debate aside, it's just a matter of time.