IMPORTANT: I fixed the startup freezes issue in v0.10.x with : plasmadesk:fix startup freezes from QDbusInterface (912f2f1c) · Commits · Plasma / Latte Dock · GitLab
as it appears no applet was the faulter. Latte just had to NOT BLOCK DBus Interface at all during startup. I believe that the fix should work at all cases. The turning point was when a user reported that the last message was observing was related to PLASMA STRUTS MANAGER...
thanks all for the help and please update as soon as possible.
The fix is part of v0.10.x and master version.
The bug report to report back your findings after testing the fix can be found at: 444739 – startup and occasional freezes from plasma default applets