Hello GrandFX1, and welcome to the forum,
Are you from Auburn Maine ? If so, you're a neighbor, just down Rt 202 a bit from me !
Sorry no Quad E2 owners have signed on to reply yet. Looking at the E2 specs sheets on-line, I've seen some that say the insert has a 52 lb capacity hopper, and other spec sheets that say it is a 47 lb capacity. Not sure why there is a discrepancy there.
But I've found with my 40 lb capacity Quad Castile that I have to 'settle' the pellets in with my hands as I am pouring them in, and pull them up under the cast top and into the corners of the hopper to get all 40 lbs in.
I know insert hoppers are harder to fill than a free standing stove, and I've read on here of insert owners using a long oven mitt, the 'lobster claw' type with just the thumb separate, to push the pellets in and 'settle' them as they're filling the hopper.
I know the pellet length makes a difference too in how easy it is to get the full hopper capacity loaded in. The short 1/2" or so avg length Oakie soft wood pellets I'm burning compact easier and have less dead space in the hopper than the 3/4" to 1" hardwood blends I've burned prior.
Hopefully an E2 insert owner will sign on and give any other advice for you. Good luck, and stay warm. Regards, DK