It is easy to make primitives that qualify as private in some definition of privacy, but the full solution that I am talking about and that Peergos has is quite difficult and the incentives for putting that effort is not there in Pubky given that the main app doesn't need it (most features can be satisfied with simpler less disruptive solutions), but it sure needs other things and will compete for resources.

More importantly, unlike the current state of pubky core, if you want to achieve what Peergos does, clients will have to get more complex (to manage Cryptrees, remember that name? :'D), in fact they will get so complex that client side signing will become a no brainer as the simplicity that justifies the current sessions model will go away.

If you still are willing to go that painful route, I think you should contact Ian Preston and ask him to consult for that transformation, since he has been there and done that. And I talked to him enough that he understands what Pubky core is.

Or wait till I get bored enough and start implementing all of this myself and see if there are good ideas there you want to copy.

Best of luck anyways.