So to confirm, you have a third-party SSD installed, and that third-party SSD does not support SMART, and a Big Sur update is mis-detecting the third-party SSD (lack of) SMART support as an error, and is balking?
I’d think your options are to then install on an SSD or HDD with SMART and image the storage to the not-SMART storage, or to replace the not-SMART SSD with a SMART SSD. Either bypass the failing SMART checks, or satisfy the SMART checks.
It’s fairly rare to find a third-party SSD that doesn’t support SMART. And given the way SSDs tend to fail (catastrophically), reducing what little pre-failure warning might be available from that not-SMART SSD; spare sector exhaustion, etc.