I think you could get away with putting the POE at the Kemper end vs the remote end. The POE spec says 100 meters.... so WELL within your 45 ft.
This would keep some of the clutter away from your performance position (one of my pet peeves ).
Ruefus is right though. Without a POE injector, a 45 ft run is well beyond what I would say is safe for the KPA by itself to push.
I am using the stock cable with a Ethercon connection to my rack where I have a panel with an Ethercon on it (I have the KPA Rack and mount it in a rack that has a patch panel on the back with all the connections for my live setup). Even with this, the fine folks at Kemper recommended that I use a POE injector since the additional connections add resistance and capacitance beyond what they recommend.
Having said that, I have been running it this way for many years without any problems..... and it is SUPER easy to set up my gig rig with the patch panel connections.
I also cover the FC cable with 1/4" plastic conduit. This makes it so my cable is never twisted up and lays nicely on stage.