That sounds like the exact problem I was having with the Monoprice mini printer I had. It could print from wifi. You would setup the wifi info then open a browser from your pc type in the ip address and you get this screen where you can print a file. BUT it is feeding gcode real time to the printer to print. Like printing from USB but over a wifi connection. I mean how unstable is that for hours and hours on end? The SKR boards all have a built in microsd card slot. Right on the mainboard. So it seems logical to me that I can send a whole file to the printer from wifi but I have not tested this theory, yet. However, I do already have 2 of the wifi modules for the skr boards and So I might try getting one up and going tonight just to see how that works.