Re: Partclone, * WARNING: The disk has bad sectors . . . MX300 SSD
The SSD does not resetthe reallocated blocks and reallocated event counts. If, however, you are still seeing the Current Pending Sector Count with a non-zero value or you see the Uncorrectable Error count increasing, then the only way to resolve it is to perform a Secure Erase. This will of course erase everything on the SSD and reset it which will usually allow the SSD to finally get unstuck and finish reallocating the blocks.
To Sanitize/Secure Erase the SSD requires it to be connected to an internal controller (USB won't work). If the MX300 is not your boot drive, then you can use Crucial Storage Executive to Sanitize/Secure Erase it. If the SSD is using hardware encryption or is locked, you will most likely need to do a PSID revert. If the MX300 is your boot drive, then you will need to boot from another drive to Sanitize/Secure Erase the SSD or PSID revert it such as usingParted Magic (I've never personally used it). It can also be accomplished using Linux if you are comfortable using it.
Feel free to post a screenshot of the SMART Attribute table from Crucial Storage Executive and provide a little more information on the situation if you are not sure if the Secure Erase is needed.