MacBook Pro 5,2 (mid 2009) 8 GB of RAM, internal EVO SSD, Multi-boot: Catalina, BigSur, Monterey Beta10,
Nvidia GE Force 9600GT 512 MB
I've had same error message ( ... required firmware could not be updated) when installing B10 from USB thumb drive with OCLP 0.3.0, and when attempting (thereafter) installation using OCLP 0.2.5. In former case (0.3.0), more then one installation was attempted; each time the Post Install Volume patch was run, it would cause boot process to stall soon after (necessary) reboot.
Had to download Beta 10 full installer onto internal drive with BigSur partition, erase Monterey partition, and then install Beta 10 onto its own partition form BigSur.
Installtion from BigSur partition was successful, however, the OCLP 0.3.0 post install patches would always cause Kernel panic. The OCLP 0.2.5 allowed installation of Beta10, and post install volume patches (after fresh Monterey B10 install)
Still, the display panel in system preferences only shows one [default] resolution and there is no screen brightness adjustment)
While OCLP 0.2.5 seems to have provided graphic acceleration, it causes Window Server to crush every time an item on the right side of the menu bar is "clicked"; there was no such problem before volume patches were applied (of course there was also no graphic acceleration). The menu bar and dock are not translucent, but window movement across the screen and window minimizing is very smooth).
Just to provide complete background; my first installation, using OTA over beta 9, went well but OCLP 0.2.5 could not invoke graphic acceleration; subsequent application of the OCLP 0.3.0 volume patches, in an attempt to achieve graphic acceleration, resulted in the described issues.
This is a report associated with use of two OCLP variants on my machine, which hopefully may lead to resolution (everyone understands the risks).
Addendum: Monterey Beta10 Window Server currently crashes (randomly) without any "provocation".
***Update 10.16.21:utilizing OCLP 0.3.1 resulted in same problems with window server, see attached:
View attachment 1867098