The original design was developed to be machined out of aluminium.
It was discovered that the test print works just fine as a mount.
Redesigned the mount to have a higher safety factor at the stress concentration.
Recommended to slice with large number of shells, prioritise layer adhesion, and slightly elevated temperatures. (All orientations has massive strength trade-offs)
Printing in the illustrated orientation is fine if layer adhesion is strong enough.
Dimensional accuracy is not very important, the bore of the wall mount can be reamed with a 13mm or 12.7mm drill bit to fit the mic arm stem.
Tested with a RODE PSA-1 Boom Arm with a Blue Yeti.
(1 year use with no significant creep in PLA)
Also compatiable with the Ikea Tertial Work Lamp.
(Using the Tertial mount for the mic arm ripped the screws out of the wall)
The author marked this model as their own original creation.