Hello to all,
I installed the 12.5 beta 4 onto my iMac 13,2 which, as others have also reported, resulted in login-loop identical to the one seen with 12.5 beta3 installation.
The common thread among Macs, which fail to fully boot and get "caught" in login-loop, is presence of the Nvidia Kepler graphic card.
I scanned the web for similar occurrences (boot loop) with Nvidia cards and found that to be a problem with other operating systems, e.g. Ubuntu (Linux), notably when the latter is updated. The commonality there was loss of Nvidia cards "ability" to find their drivers and / or presence of a secondary Intel Graphic Card or drivers. The final result was a boot-loop very much like iMacs'. There was a proposed solution, to modify some boot parameters, but it applied to window system and terminal commands evoked do not seem to have Mac OS equivalents.
However, when I looked at the screen output from OCLP patch 0.4.8n installation, I noted that patch seems to install Kepler Drivers, as well as drivers for "graphics Intel Ivy bridge" cards. While above correlations are tenuous at best, would it be possible to remove (or Block) Intel driver installation from the Volume Patcher (when used in iMacs with Kepler); that would result in Kepler drivers installation only. It is possible that in the past two betas, Apple changed how graphic drivers are "called" during boot process.
One more data point: while enabling "auto login" in system preferences does not seem to prevent login-screen looping, the command listed below did work on my machine (to bypass login screen), when executed form Safe Boot via terminal.
Command: defaults write /Library/Preferences/com.apple.loginwindow "autoLoginUser" 'username'
Replace 'username' space holder in above command with an actual user name used to login into the computer (omit quotation marks, e.g, drakes and not 'drakes'). Do keep quotations around "autoLoginUser".
When booting after executing the "auto-login command", computer progress stalls at the near end of progress bar, screen turns gray, and fans go to maximum. It is reminiscent of kernel panic. Shutting down the computer is the only viable way to leave the "grey screen of computer panic(?)".
Hope this may be of help.
One more data point: Installed Monterey 12.5 beta3 on MacBook Pro 5,2 (2009) without a problem; machine is fully operational, including graphic acceleration (used OCLP version 0.4.8n).