[Brian of Aquanauts]

It's a pity you were only taught one solution to that problem.

It makes for a good debate, and gives a good range of problem solving skills if you can have lots of alternatives for problems like a lost deco gas.

Skills that are worth knowing, and often discussed on a GUE Tech courses:
Lost deco gas, share team members gas V back gas solutions
Altering deco profiles / the Oxygen Window
Addition of deeper stops / ascent rate variation
Use of bubble models vs buhlmann
Emergency ascents, re-decents
Use of support divers
Emergency protocols
What deco you really need to do to avoid a fast tissue bend in an emergency

The GUE Tech 1 course is like a combined Advanced Nitrox, deco Procedures, Normoxic Trimix and Advanced Line Laying, so goes into things in quite some depth. Maybe you can get your Trimix instructor to cover some of the above.