Ok , I would spend expensive 1:1 time for nailing different hard topics like timed ascends, precise buoyancy, basic task loading - smbs deployment with no reference and get used to your equipment.
Also practice building a tech mindset. I am not trying to nick you or being rude, just trying to share mu experience, but phrases like “playing by the ear” and tech diving are totally incompatible
you must know exactly what you want and have a plan. Several dives are not that much, actually.
The reason why I would not recommend putting another bottle (even if it’s simulated) you need to first learn and build good understanding and reasons why certain protocols exist, gas analysis, why it’s important especially with adding extra gas like deco and all the stuff that goes with that. Its a whole subject and you do not know what you do not know.
We did deco simulation in my tech class before using a real gas but we learned all the other elements of it before that.