FYI, I have seen multiple boot loops with the M-series Macs and they are indeed very frustrating since you are unable to detect any usable clues to figure out the problem unlike older Macs. However, I have found two things which can help:
Clear the NVRAM using the command line while booted into Recovery Mode:
nvram -c
Sometimes a person may configure a legal setting through the GUI and a macOS update could break things (happened to my organization a couple of times). It happened to be a display related setting which prevented the system from booting or even showing video on the screen after a few boot loops. If it still won't boot & you cannot access the Startup Options screen again, then clear the NVRAM again, but this time choose Shutdown. I like to first press the Caps Lock key so its LED is lit so when the system powers down the LED will go out so I know when it is completely powered down. Then press & hold the power button to access the Startup Options screen.
The second thing which can sometimes help if you cannot even access the Startup Options screen would be to perform a DFU firmware Revive which resets the security enclave chip & system firmware. This may give you one chance to boot into the Startup Options screen....if the system tries to boot normally or even in Safe Mode, then it may pull in a setting & get stuck again until you perform another DFU firmware Revive. Unfortunately the DFU firmware Revive requires access to another Mac capable of running the latest version of macOS which at the moment is Sequoia. Again, after authenticating to "Activate the Mac" after the DFU firmware Revive, it is best to choose Shutdown if you wish to boot to the Startup Options screen.
Third item which can help is reinstalling macOS over top of itself. Most times this won't do anything because the OS system volume is now a read-only signed & sealed volume, but it must affect some unprotected boot or configuration files and possibly the NVRAM as well.
This all illustrates why backups are more important than ever before, because there are a lot more new ways to permanently lose access to the data stored on the internal SSD due to all the hardware, software, and security changes. The data many times will still be there, but there is no way to access the data.
Hope these tips may help you & others in the future.