As it turns out, my Palm Tungsten C hotsyncs just fine to a Raspberry Pi. I think I’ll spin up my unused spare Pi to be my handy hotsync server!
@jynx got it all setup and it works great... still cannot sync the Treo 90 — “missing endpoint” is listed in dmesg, same as all my other PCs. Oh well. I own a legit copy of Teal Backup.
"I appreciate SDF but it's a general-purpose server and the name doesn't make it obvious that it's about art." - Eugen Rochko