Nice work there, when installing my atmos in-ceiling I ran into 2 issues.. perhaps this might help out if you plan to buy the axiom's atmos speakers

1st I have 1/2 inch drywall and when fixing the speaker in place the little legs don't quite make it because the drywall is not thick enough & had to build up the thickness from inside ceiling ( I used paint mixing sticks cut in 4 for each speaker & duck taped them to where the installation peg would sit

2nd is the grills.. hard to remove without damaging them (used axiom paper clip suggestion)