Spinrite was originally just a diagnostic tool. It will probably give you more details than necessary or you know what to do with.
The problem with SSD’s and diagnostics is SSD’s have a controller preforming all kinds of wizardry and witchcraft between the flash memory and the motherboard. This is because drive makers are cramming more and more into the same space.
In all likelihood your drive is failing or your motherboard is. You can’t do anything about it except replace the failed component. Diagnostic tools might help identify the problem, and might not help at all. Tools like Spinrite rely on the drive controller to tell the truth. If it’s lying, fudging, or broken you’re SOL.
Fanless PC as an OPNsense router. Probably somewhere between $100-$500 USD for the chassis and remaining parts depending on what you want it to do and how fancy you want to go.