Good to hear that it worked for you. What specifically is your hardware ?
https://www.tonymacx86.com/account/account-details
View attachment 495142
No, I'm not planning on that for a number of reasons.
Even if you go through switching SMBIOS to one that is Big Sur compatible, it will only last for one upgrade. Mac Pro 6,1 is one example. I don't really see any significant advantages of Big Sur over Catalina. In my opinion it's also not worth all the work of switching to OC on this build.
General recommendation to all Optiplex 7010/9010 owners
Stay with Catalina 10.15.7
It will continue to get security updates from Apple for about 3 years. Will keep working with no problems, you'll be able to keep using supported updated 3rd party browsers like Chrome and Firefox.
If anyone does want Big Sur, first learn about OpenCore and how that works and then give it a try.