I designed side covers for the Apex Frame. They fit perfectly in combination with the Vista Mount (https://www.thingiverse.com/thing:5961253) and the Vista Antenna Mount (https://www.thingiverse.com/thing:4747635). You have to add the hole for the USB port yourself (most slicers have such a function)
ApexFrameSideCovers.stl | 193.7KB |