For SSD drives, the Trash History and Directory backup features have been disabled, as described above. Volume usage and email alerts are unaffected. There is a lot more to TechTool Pro than its system preferences pane.
We have already recommended that people not use disk optimizers on SSD or hybrid drives, because they would interfere with wear leveling.
You can still use the Surface Scan test on SSD and hybrid drives to check for unremapped bad blocks, and the Volume Structures test and Volume Rebuild tool (provided there is enough free, contiguous disk space for the new disk directory files to be written in a single piece each). The File Structures test is unaffected by whether a drive uses flash memory.
There is no reason why S.M.A.R.T. testing cannot be done on SSD or hybrid drives. When these drives were new, the S.M.A.R.T. tests from all vendors had to be updated to report the data correctly for them:
Can you use SMART tools with SSDs?, by Aran Pitter