Gear requirements can also be instructor specific. I always required Shearwater computers for tech courses along with a back up bottom timer or second Shearwater.On the Scuba Academie website, it says this about configuration for TDI Intro to Tech:
Double 12 + wing (no bungee)
Double regulator set with long hose setup
Spool + SMB
Reel (on loan if needed)
Drysuit
Canister light + backup light
Wetnotes
Mask + backup
Compass + Bottom timer/computer
Sturdy fins
I couldn't find any specific configuration requirements om the TDI website.
It was also acceptable to be in doubles or sidemount after I verified sidemount skills.
I also required the student to have at least 25 dives in the configuration they were going to use because I was not teaching a doubles or sidemount class.
Gear was also subject to changing things around when necessary and for rejection of equipment if it didn't make sense or posed a risk to the diver.
When you start tech training, you basically have to empty your head of all the BS that you got in recreational classes. There's no such thing as "good enough" when it comes to buoyancy and trim, buddy skills, communication skills, and planning.
You either have it or you don't. If it's not good enough as determined by a pool session or fun dive and an interview, you get to go away and work on those things.
Otherwise the diver is a risk to themselves and their buddy as well as a drag on the class.
If not up to snuff there's always the option of a private class where those things can be addressed for appropriate compensation and additional time required. That was never a favored option.
I rejected a few people for tech training who didn't have the necessary entry skills or didn't understand the level of commitment required.
And one who wanted to argue about the fact that if I felt he wasn't up to standards at the end of the class, he wasn't getting a card. Could not grasp the fact that he was paying for training and not a certification.