I guess I should have read that spec myself. Ideally I would put all APs where they are would work and function the best but these mounts kind of suck. In high end residential these will never go in a finsihed, used room so in order to sell them we have to be creative. If they were flush mounted to the ceiling like most other brands there would be a better chance but not with these stand off mounts. I'be more apt to use the dropped ceiling bracket on a sheet rock ceiling then the mount sent for that purpose. In high end even flush mounts are difficult to place the AP near where they would work the best. I don't even think these would fly in most commercial jobs either.
These recessed trim rings are pretty nice, could be slimmed down a bit and if they were available for $35-$55 each that would be a good value but in this link they're way too expensive. IMHO it would be smart for Aruba to work or attractiver installation options
https://static.graybar.com/content-resource/pdf/1042-ap315-oberon-wireless-25925321-spec-sheet-sku-spec-sheet/202e26b85b12a11a7388b1714140a0ac-1002388.pdf