Agree with you, and lot of customers are on the same page as you are.
For SQMSQL, I doubt that support will be added, infact all the newer MS-SQL releases aren't even tested for MS-SQL, so there is risk to adaptation of newer MS-SQL for whatever business demand, if we cannot back them. I guess, sooner or later we may have to move on. To be honest, we are still running 9.1P13 (we are going to be upgrading very soon to 9.5) and while we still love SMSQL, we are already preparing for SnapCenter for SQL move, so far we have moved VMware stuff only.
Looks like P1 is posted on 21-04-20, which has following fixes. Not sure, if any of these have affected your setup. Interesting it says, link to SnapCenter 4.3.1 has been disabled, upgrade to SnapCenter 4.3.1P1 version
Bugs fixed in SnapCenter 4.3.1P1 :
1312391 :Snapcenter fails to run schedule job with error message "TOKEN EXPIRED"
1310240 :Updating the storage SVM password post to upgrade from SC 4.1.1 to SC 4.3 has removed the storage connection from SC Server.
1310246 :Secondary Backups are not working post to SVM password change and readding the lost SVM back into SC.
Thanks!