i've not yet started my ergonomic gadgets journey but just being aware of the elbow->hand connection has helped me
VIA is proprietary and not really an official QMK thing (QMK is free software). There is also Vial[0] which is free software if you want a GUI, and the QMK configurator[1] web app (but this lacks some features like enabling mouse keys or NKRO).
Lastly I want to add that Workman[2] may be preferable to Colemak Mod-DH. Rather than an attempt to fix major issues in Colemak like Mod-DH, it's a whole new layout that avoided the issues from the start. I have also heard from some that it had ortholinear and columnar stagger boards in mind with its design.
I type on a Pinky4[3] keyboard that I assembled from a kit. More keys than your keyboard, but a similar idea. I was coming from a 60% and wanted a similar amount of keys. I've been quite happy with it.
A bit benefit to the esoteric keyboards like this is the ability to use your thumb for more keys, and being able to not have to use the pinky fingers as much.
https://i.redd.it/lfqcys91rg291.png
https://i.imgur.com/2fZyLxV.jpg
(images from reddit)
It's very easy on the hands and I never have to guess where my fingers are. It's also easy to learn, and you won't lose your row-stagger proficiency. It's like learning to type on your phone. If you change the ergonomics of the situation (cramping hands in the middle (regular keyboard) versus sitting upright with hands at shoulder width (split keyboard)) your brain will interpret it as a new, separate skill.
Also, the switches can be laptop-style or regular, and they are much smoother and easier to press. It'll take a month or two to really get up to speed but maybe abandoning a learnt skill is the way forward here.
Also, the firmware for these keyboards is painless - QMK now has a GUI (VIA).
Edit:
Switching to a better keyboard layout will also help. Colemak Mod-DH is MUCH better than QWERTY, and has the most-used letters on the home row and enables rolling motions.
https://colemakmods.github.io/mod-dh/