After installing DF 10 beta 18 my Windows 11 becomes very slow, not everything but I noticed it especialy when using browsers (I tried Edge and Firefox). I shutdown and restarted Windows after the 10.18 installation but this did not help. After going back to DF 9.9 everything went back to normal.

Not really, it's about the same as when 9.9 is running and I try to open a new tab in Edge (for example). Maybe the Display Fusion process has a bit more memory usage (about 40 MB more - 120 MB), but this is also the case when I'm not doing something that is now slower than with 9.9.
I did notice that regardless of what I do ESET Service (my virus scanner) has some disk activity (about 3 MB/s) that does not occure when 9.9 was running. But pausing ESET does not speed my system up so long as DF 10 beta 18 is running (or stop the disk activity, so probably not a valid test).

DisplayFusionDebugInfo.zip

Yes, after disabling application hooks and restarting DF everything seems to run at normal speed again.

Re-enabled the application hooks (also immediately bringing back the issue).
Quit version 10 beta 18 and installed version DF 10 beta 17 (the link you provided).
After that everything still seems to work at normal speed and the application hooks are working as well.

I saw beta 19 was out, so I tried it.
The memory issue with ESET seems to be gone but I still have the same issues (slowness) when browsing, and so reverted back to 9.9.

With all the 10 betas I've tried (17, 18 and now 19) I also noticed that my system icon tray somtimes opens in the upper left corner of the screen.

I've been running beta 22 for about a week now.
And all the issues I've mentioned before seem to have been resolved.
Thanks.