Hi Jake, we had a number of discussions over the years on Treat (and modeling tools in general) in the RESNET BPI Group on LinkedIn. Many of those threads are now archived in the Home Performance Archives (see HP Forum Archives tab on menu bar, above). I don't recall any discussions on training resources but I just searched the archives to be sure and came up empty. Sorry.
Hopefully some Treat experts will see this discussion and chime in with something useful for you.
BTW, while searching the archives, I stumbled across a 'classic' discussion from 2012 (actually a debate) on the merits and pitfalls of energy modeling in general: Green Jobs Green New York off to a slow start.
Wow, I remember that thread as if it were yesterday! Here are a couple of comments in particular you may find useful as you're learning Treat. Keep in mind these comments were written in 2012, so some of the pitfalls have been addressed in subsequent versions.
I'm going to start a new thread to point folks to this discussion as I think most of the sentiments expressed therein are still valid.
Thanks David... I'll give them all a read and will welcome any new info.