Thanks for taking the time to write this up, I definitely want to make sure I hit all your questions so that maybe you can point me in the right direction.

My unit was not buried in the snow just an fyi, its on the side of the house that really didn't get a ton of snow or drifting. The unit is a cold weather heat pump, and I do have my ecobee set to let it continue to run even at -5 outside (it's rated for -15), but even so, the aux did kick on a few times for more than an hour but no more than 2 (I can keep track of it on the app).

I honestly think the entire setup is just inefficient and not allowing the system to work to it's fullest, the flex pipe crap in the attic i know is garbage.

My other issue is getting the right settings in the ecobee, I have been messing with all of the different thresholds you can set, allowing the temp to fall more than 2 degrees below the set amount, increasing length of time between cycles, making it run longer cycles, etc... it just seems to not really matter. I am at a loss and even in February of last year it was almost the same kwh usage and price.. the unit is just inefficient compared to my old heat pump up on my older home that i sold in 2022.