Maybe your keyboard was a contributing factor? I had wrist pain typing in vim on a "regular" (Keychron C1) Keyboard. The wrist pain is gone since i use a split keyboard (Ergodox EZ) which allows me to rotate both halves of the keyboard in order to match the "incoming angle" of my forearm which removes the need to constantly bend my wrists outwards.

It was indeed, and I went through an incredible range of bizarre alternative keyboards (vertical keyboards, DataHands, etc), but the simple fix ended up being the timer apps mentioned, along with a very standard MS ergonomic keyboard.