Basically all GPS anchor trolling motors are bow mounted. I assume you could fabricate a mounting plate and transom mount it, but it won't perform as well.
It's going to take more power to push the transom of the boat around compared to the bow. As mentioned previously, it'll also hold you transom into the wind and current. The auto route and hold heading features will be backwards if you transom mount it, and there is no good way to fix that. If you're manually driving it with the remote, as long as the trolling motor head is facing forwards, left will still be left and right will still be right. But, like I previously mentioned, ALL autopilot or heading specific automatic features will be backwards if you transom mount it as they are all designed to be bow mounted.
Once you're using the GPS anchor or spot lock (or whatever your manufacturer calls it), the GPS has no way of knowing which direction your bow is pointing. When the wind or current shifts, your boat will pivot around the trolling motor. If you're using a real anchor up front, i'd think this could cause issues and the trolling motor GPS won't be able to keep the boat in the same orientation.
I do a lot of wreck and structure fishing with my GPS anchor trolling motor. It's a game changer. I also used to use two anchors to get my boat position and direction perfect, but I find that a single bow mounted GPS anchor trolling motor is sufficient. You'll mostly stay bow into the wind/current on the trolling motor GPS anchor, and if it shifts, its easy enough to just hit a few buttons and adjust the boat. I bet that you'll quickly stop bothering with the real anchor at all once you get a GPS anchor trolling motor. Once you get the hang of it, you can stay parked on top of an exact spot easily.
I'd also highly encourage you to just bow mount it.