Given densest PM packing of an a n-gon with a 4-fold rotational symmetry it possible to construct P2MM, C2MM and P4GM packings in https://milotorda.net/index.php/packings/
Here is an example for an octagon. P2MM, C2MM and P4GM packings based on densest PM packing with exactly same density 0.8284271. From left to right: PM, P2MM, C2MM and P4GM
