I would keep the controller on 1.4.3. It still supports all the F modes, and still works with the P4, with the switch layout controlled by the P4 inclusive DJI GO app, or the prior layout on a Pre P4 version of DJI GO.
My modded GL300A controller is on 1.4.30 like yours.
P3P aircraft are 1.4.10+ (was 1.1.9, but it now displays as 1.4.10+ even though I never updated it) and 1.4.3 and 1.5 on my P3P replacement from DJI (they disregarded my request NOT to update the firmware!).
App is 2.30 or 2.4.3 (pre P4, as I have a separate dedicated P4 iPad with 2.7 on it). I also have one used W323 P3P arriving this week, with the very latest DJI firmware, and will be testing for any performance limitations. Any aircraft with 1.5 or later on it cannot be downgraded more than one version number.