Thanks for your reply, and thanks for the great addons!
I am on 2020 and the TBM has never remembered the fuel load between sessions. It does remember the payload, but never the fuel. I believe it works correctly on the Duke, but I am not sure at the moment.
As for the prop deice, I was in fact using the default toggle event through SPAD.Next, but the switch wasn't animated. However I just noticed the B even B:DEICE_Propeller_1 and setting it to 1 or 0 seems to work: I get both the green light and the animation. The Toggle event was only giving me the light, no switch animation.
I'll experiment with the _IsDown addition to LVARS. The Annunciator TEST and the gear down test have neither sound, nor animation, whereas the deice light test, ECS fault light test and the ITT test work correctly.
Cheers!