How to get Xbox media remote working with PHT on Ubuntu 16 / Intel NUC



I've got PHT installed on ubuntu 16 in my Intel NUC, and got the Xbox 360 media remote working about 90% with ir-keymap. Problem is that no matter what I try I can emulate the escape key behaviour to return to the previous menu. Using ir-keytable -t returns the correct key code mapping I've set (KEY_BACKSPACE currently, but KEY_ESC and KEY_BACK do the same) but Plex just seems to ignore that particular key. I've seen some evidence of similar issues on NUC but I just can't get it working... does anyone have any suggestions?