This might surprise you, but Fallout: London - the big Fallout 4 mod - is proving pretty popular among Fallout modders who aren’t part of Team FOLON. Some of the bigger New Vegas fans among them have even started bringing that game’s faction rep and disguise systems to Blighty.
To be fair, some of them have already done the obvious things mod-wise, such as offering you a cure for your character’s crippling dog food addiction, and it looks like they’ll have to wait a little while to be able to enjoy Fallout: London’s cut Wild Card main quest arc, so let em have some fun in the meantime.
‘Faction Reputation and Disguise System’ by Invatorzen looks to be the most comprehensive attempt so far at allowing you to officially have it confirmed that you’re the most vilified individual in London, rather than just knowing so because every NPC won’t stop shooting at you.