I am curious -- how is the INDI Server performing the file copy to the Ekos client when you have it set to store the files on your client? I recently installed and set up a 5G WiFi card on my Pi, which is working well, and about twice as fast as the built-in networking adapter. The problem I have is, there was no improvement in the time it takes for the file to transfer from INDI to my client. Other file copy tests (with the same FITS images from the camera) move much faster on my network, but for some reason the INDI ones don't.
EDIT: Disabling IPv6 on the Pi, and rebooting the device and my router as well, solved the problem. I now get about 8 second downloads with the large frames of the ASI 1600 (32MB files) and I tested my camera that is on order (QSI690) with the simulator and it looks like I will get 3-4 second downloads with that. Perfect.