Yep ok ... im doing the Actron Que for many the same reasons. The efficiency on these new models with digital inverters etc seems great.
The challenge for a return air duct on the two storey house is the limited space they’ve got to run it, and get it in a riser up to the second storey roof as well. I had this challenge in our old house, there was not enough space in the riser to get another duct through.
If they build it in the design of the house it should be solvable, but again with a volume builder they’re not going to want to do this.
The solution in our old place was a passive air return duct .... ran through the bulkhead with a few bends (the dead vent concept) and then hopped it over to vent into the antechamber to the cinema room, and there was then a final vent from that room into the main area of the house. The final vent I didn’t even bother boxing up, there was no impact to the sound proofing solution at that point.