I went ahead and installed Cindori Trim on my MBP (mid 2010, Yosemite, 500gb 840 EVO with firmware update performed) When will the trim/kext issues surface (i.e. the grey screen of death)? Reboot? Reboot after an Apple update? I understand it happens if PRAM is reset (does that ever happen without resetting PRAM intentionally?) In order to avoid the workarounds and restart protocols - when would one want to disable the trim? Should one turn off autoupdates from apple if trim is enabled? Then disable trim and do periodic updates manually?