Hello :) I am back :)
Please move this to the appropriate forum once you created it.
I just installed the first beta of Monterey (MacOS 12, 21A5248p), and it worked, but it did have some hickups. From a first, quick analysis what happens is that the driver for SoftRaid gets disabled by Monterey. So you need to log into the system using a user where the home directory is NOT on the SoftRaid-driven external HDD (unlike my main user). Once you do that, the installation will finish, and then a notification from the OS will pop up, saying some extensions have been disabled, and the system extension cache needs to be rebuilt. There will be a button directing you to the right settings screen, you need to click the lock and login, click on "Details" to get info about which extensions needed to be updated, and then the System Extension Cache will be rebuilt. Once that is done (which requires at least one restart), everything works fine. If you login with a user with their homedir on the SR-drive, the installation will just fail with "unable to login at this time".
BTW immediately after the unattended upgrade the system (M1 Mac Mini) booted into Recovery Mode. No idea why. I just restarted it from there without doing anything, and then everything ran its course...
So yeah, SoftRaid will work with Monterey.
I would rather you and others wait a few days (possibly less, but lets see) when we can get a SoftRAID beta out. It may be possible to make it work, but we need to test, as it is unknown what changes are in 12.0, and how stable it is. It is being tested already in house, unless we run into something, its likely this week we can have something.
Here is a link to the SoftRAID beta for Monterey. This is a perma-link, you can always go here for the latest version.
No significant changes from 6.0.5 in beta 1. Future versions will have more significant changes.