REPAIRED FPS≈1 on Nouveau Compiz'ed Desktop. OK after env var vblank_mode=0 has been set.

Extremely important! I thought it was internet browser problem, when disabling FireDragon graphics acceleration not helping!!

Export the variable vblank_mode=0 in your /usr/bin/start... file (a file that runs Xorg / session pair soft).

-or- 

If you have Linux DE that starts in a systemd service, runit or similar: add the export to proper DE startup place.

I do not know how to resolve potential problems under Wayland/Sway/Weston/etc – except you need nouveau, NOT the nvidia/nv driver (various names under Xorg?!!).

For me, LXQT starts from two files to debug dbus (now OK), and startup commands (from script: BAD, desynchronisation of when-or-if xmessage program appears)

(From linuxvox service, but who knows that COMPIZ need its application too?? Noy only at glxgears performance test!!)