MacBook Pro Retina 2014 Mid under Big Sur crashing always

Hello, my Macbook from Mid 2014 15", is always crashing caused by a Kernal file called 'AppleThunderboltNHI.kext', since Catalina i needed to rename the AppleThunderboltNHI.kext to dont get a blackscreen. That for i had a workarround that always worked fine till yet...

https://outluch.wixsite.com/rmbp-crash (das war die vorhergehende lösung die ich genutzt hatte)

This method doesnt work anymore under BigSur so i found another way under https://forums.macrumors.com/threads/big-sur-and-applethunderboltnhi-kext.2267818/page-2 how to do it, but that also doesnt work for me.

csrutil disable
csrutil authenticated-root disable 

Worked so far

Now i need to mount the harddrive as root

mount -uw / 

gives me a Error even if i try to mount my hard drive

mount -uw Volumes/Apple SSD 5120F

unknown special file or file system ...

Also wondering why my harddrive has such a wired name in the disk utility tool. Can anyone help me how to rename or remove that file to fix this permanent crash. My macbook is starting and after 5 - 10 mins it randomly crashes > gets a blackscreen and the vanns are turning up for 10 secounds and then the macbook shuts down. I realy need to fix it, the crash doesnt happen if i plugged something into the Thunderbolt slot on my Macbook. I found out its happening on several Macbooks from 2012 - 2014 and alot of people having that problem. I would be happy about tipps. Thanks in advanced for your help.

Regards.