24 pin cable goes to MLB. Not drives. How did you confirm that brownouts were the cause of your issue? And not controller resets, or what not? If there were brownouts on ATX supply you would get system resets, not file corruption or drive disconnects. Or are you referring to those garbage “modular” power supplies with another set of gimmicky connectors on themselves instead of soldered cables coming out form a large opening or a PCB tooth?
You are making a lot of claims without evidence. For all you know issue may be still there. I would replace power supply at this point - because you don’t actually know that’s the issue is, only that it may be related to power delivery. Especially since your supply allows the cables to “come loose”. This is not normal and should not be ignored.
On your questions: leave it be. What’s corrupted — corrupted. The rest works.
If you suspect the hashstore itself is corrupted as opposed to logs — yes, you can rebuild it. Script to make write-hashtbl easier to use