are you sure??...i definitely do not think it's a maxima....in fact, i believe barely anyone in north america beyond, maybe, a few academic institutions or public aquariums have a true, bonafide a. maxima......it's not that it's rare or expensive......it comes from a specific part of the world where export is strictly illegal.
in fact, practically all "maximas" i've seen look like scolymia sp., a. echinatas, a. hillae, a. bowerbanki, lobophyllia sp.
no one will ever be able to tell for sure anyways.....you will need to look at nothing less than a skeleton or a CITES export manifest given the immense amount of pushback you'll get from people when you proudly declare "i have a true a. maxima"
just my $0.02
Zach