I just installed FSUIPC and trying to do the same you did. But first of all I'm not really sure where I have to put the flybywire-aircraft-a320-neo.evt file and if there is something else to do in order to let FSUIPC configuration that there is this new file.
In fact, when I enable the Events log, even if I change something on MCP panel (autopilot) I still have in the log "standard" commands like (example) AP_PANEL_SPEED_HOLD etc etc.
Instead I expect to have something like the new custom commands (example): A32NX.FCU_AP_1_PUSH, etc. etc.
Did I something wrong in my config?