I have performed full pid scans on other GM vehicles (gen 2 CTS-V, cobalt SS/SC & cobalt SS/TC) and found the unpublished IAT2 PID and shared it in the torque forums a couple years ago. To do this, you have to install torque and torque scan plugin, launch Torque Pro and pair with your obd2 adapter, put the key in accessory (which may be difficult to keep in accessory mode for longer than the 5 min shutoff time on the SS), load torque scan, go to menu and PID scanner, menu, start scan and wait for it to complete. There are typically 3000-5000 pids, so it takes as long as your scanner can read PIDs. The cheap elm units typically get 7-15 PIDs/sec. The obdlink mx supposedly get into the 50-100+ PIDs/sec. I have yet to pick one up - but I plan to.
The trick is the output of the PIDs is in hex, which you have to convert to decimal. The tip I have to share is by not having the engine running in controlled conditions (knowing the ambient temperature and the car being cold, all the temperature PIDs will be easily recognizable). IE: if it's 68*F, that's 20*C, convert that to Hex and you have the value approximate of whatever temperature probe/PID you're looking for. Then after a full pid scan, you can email the results to yourself, and copy the output to excel and convert the hex data to find which PIDs are of interest. Then you can setup a few of them plugging the pid register to some copies of the particular temp formulas desired (ie: trans temp), take the car for a drive and see if the values seem realistic. It's completely trial and error, and it took me about 30 tries before I found the factory IAT2 temperature register, but you will eventually find it. Then you can make custom gauges to use and have them flash when hitting a particular temp as a warning indicator.
I know this was maybe too much detail, I'll share more when I finish polishing up my SS that I got a couple weeks ago. I plan to do a full PID scan, what would be all the values of interest? I'm sure the typical oil temp, transmission temp, IAT if it's not already there, timing, kr, coolant (should be available for default).
All the torque PIDs that work by default are helpful, I've easily diagnosed bad coils and injectors by using the misfire counters and swapping coils and injectors around to see if the problem moves to a diff cylinder or not. Torque has been a very helpful tool in many ways. I wish it had been ported to IOS, but there are others now available in IOS that I will play with once I pickup and OBDlink mx wifi.
I hope at helps add some value to this thread! Good luck!
Matt