With some specific workflow I use in some cases (involving leaving long-lived intermediary artifacts), this turned into me pasting a path to handover file in previous agent's session, and handover itself directs the agent to key files from that session to read, and that's it. So far, with this process, at no point I felt any quality degradation (though early on I often see "I need to check how my predecessor did ${something}", followed by surgical spelunking of past chat's history), even as I carry a single piece of complex analytical work over 5+ sessions.
Do you have a public repo for your approach?