You brought it up before but what’s wrong with IsolateDestAddr and IsolateDestPort?
Unless someone uses a browser that way the performance impact shouldn’t be crippling. Enabling it for browser’s slows things down because every webpage resource and ad from a different domain opens up additional circuits.
Not 100% the same, but very similar to this, see:
Right but is there any way it can be enabled for everything else except for torbrowser and uwt apps?
There is, but it’s recommended against for similar reasons and due to the load it would create for the Tor network.
Source: Nick Mathewson, Chief Architect, The Tor Project, [tor-talk] Tor's stream isolation features defaults