RadioMaster GX12 MOd: Shoulder Buttons
No matter what controller you choose, it won't be perfect. There's always something small you wish they'd done differently or some improvement that could be made. Personally, I absolutely love my Radiomaster GX12 but when I moved from the Boxer Crush to the GX12 I really didn't like how I had it set up for arming and disarming the quad.
On the Boxer there are two shoulder buttons, one is momentary and one is latching. I loved this setup as I could set the prearm on the momentary and arming on the latching. I found this a safe and intuitive method. However, on the GX12 out of the box the position of the buttons is instead populated with two switches.
I sometimes struggled with the switches, as I'd come in to land I'd flip the switch the wrong way and wouldn't get a positive and instant disarm - often leading to a bounce or not landing on the target. As it turns out, the GX12 is really easy to modify with a couple of standard switches to achieve the same configuration.
There's an STL for custom shoulders that fit a standard 12mm button thanks to LucaLombardo on Cults3D, you can grab that here. I was not particularly bothered about the looks for this mod as it was purely functional for me, but I had some transparent PETG lying around so I used that - which actually turned out pretty good since the SA and SD buttons have LEDs in them.
The shoulders are retained by two small screws which require a 1.5mm hex to remove. This will give you just enough access to remove the existing switch and replace it with an alternative. You can see in the photo above that I've got a red latching switch for arming and a black momentary for prearm.
Whilst I can see a lot of people wouldn't bother with a modification like this, I'm really happy with it and glad I made to change to standardise things between my two controllers.