Hi Saiyan, I'm the developer.
The Scanner never writes to SSDs while performing a surface scan and therefore does not in any way impact the lifespan of the SSD.
However, SSDs do benefit from full disk surface scans, just like spinning hard drive, in that the surface scan will bring the drive's attention to any latent sectors that may become unreadable in the future. The Scanner's disk surface scan will force your SSD to remap the damaged sectors before the data becomes unreadable.
In short, there is no negative side effect to running the Scanner on SSDs, but there is a positive one