One rather simple solution from FDEV could be soft PVP-flag. "I do want PVP"/"I don't want PVP" always in PVP wanted position if one has pledged to Powerplay. Now said flag would not actually prevent PVP actions, but would show in scan or just by targeting ship. Nothing prevents discourteous commander from engaging, but well that removes any kind of argument for blocking said commanders.
You know, you can just talk to people & find some common ground (or more likely, common enemy).
Couple of examples:
One of 'my' stations got attacked by Thargoids a few years ago. During the initial attack it was a pretty busy system & there were a few pro-xeno attacks, I spoke to one player in a t-9 (I was using a Cutter to haul in repair commodities) who was angry they just got blown up. I asked them to check their history tab & give me the name of the Cmdr that destroyed them & sent that Cmdr a friend request for a chat. They were nice enough & explained their reason for being in the system (pro-xeno). Fair enough I sait, I'm not anti-xeno this is my home & I'm just repairing the station. I asked what anti-xeno role a Cmdr in a T-9 would play & he kinda had to concede not an effective one & he agreed to leave us to repair my home station. I showed respect for his playstyle (ie I didn't call him a liar or complain about them. He left the system alone & I made a firm friend in that T-9 Cmdr, they helped me to repair the station & I showed them the BGS ropes, gave them motivation to keep playing after a poor (for them) initial experience.
I was trying to flip a system to one of my factions, that faction needed a source of bounties & I knew the existing faction had one already. It was a contested war but I was winning with help from a couple of friends. One of my friends was a PvPer, not that happy to do grindy work for me but it was something to do & CZ work is at least more fun than hauling or gathering explo data

We had a spare slot in our wing so they invited another PvPer they knew that was online at the time to share mission rewards & when that Cmdr popped over a friend of theirs, wondering why now two other PvPers were in some random system off the beaten path & decided to see what was going on. They joined the CZ we were in & with impressive efficiency took all four of us out one by one.
I respawned in the local station & sent a friend request for a chat. Congratulated them on their impressive skills, figured out the whole story & then quickly explained why we were all here & joked that this Cmdr that killed us all now 'owed me a favour'. They spent the rest of the evening doing CZs for us & the other 4 all shared mission rewards for rebuy cash while I worked alone. Made some friends, and as a side effect distracted a couple of Deciats most notorious 'gankers' for several hours.
It can work. Not every time I'm sure, but it's an option that doesn't require any changes to be made to the game, just talk to people respectfully & see what happens.