I’m surprised that the hrTSS and power TSS are so different. I’ve never used the power TSS but in theory it should be the most accurate. I suggest sticking to one metric and since you have Watts I’d do that.
It might be interesting to do the HR drift test and compare the AeT it generates to the 2mMol power you got.
I would do the base work below AeT as normal but I would recommend using a time trial effort for 30+ min to see what your AnT power is. For endurance training you will want to be training at or above that wattage.
I long for the simplicity that is possible when you have pace or power to control your training. A luxury we don’t often get here.