For debugging purposes, it's helpful to have a logfile per device, especially when a user has the account setup in several devices, as the user-log-file gets quite crowded.
Ideally there should be a way for the admin (via config file) or the backend (via a method) trigger the logging classes to write a specific log file for a device and only log there.
As on one device several users can be configured, ideally this would be a combination of user & device, so you have separate (or no) files for a specific device+user combination.
With the code of
ZP-972 it's still possible to get a single user+deviceid log, by having these checks in backend and triggering ZLog::SpecialLogUser(), but this will not work if you want separate logs for one device with 2 users.
All this should be possible with the implementation of this ticket.