Just wanted to say thanks. 3rd method + Clover Configurator works perfectly.
A few days ago I used the kext patch method I found elsewhere. It enabled TRIM alright, but broke my sleep -- the computer would wake, then promptly reboot with a kernel panic. Undoing it somehow broke my Magic Mouse and I spent a few hours reinstalling kexts, rebuilding cache, etc. until I got it back.
The 3rd method + Clover Configurator just works. Which makes me very happy.