When I bought my two M BRACE RCA units, I also switched to the Microsoft Natural Keyboard Elite. In combination, the pain went away, and the keyboard prevented me from continuing to injure myself.
The successor to the Microsoft Keyboard Elite (now discontinued) is the Perixx PERIBOARD-512 Ergonomic Split Keyboard. You can find it via any Amazon website search box by entering the Unique Amazon "ASIN" Number(s) as follows: B075GZVD4T (Black) and B075H1D95N (White) as of August 2022. Both colors were priced at $45 with 4.4 Stars and over 10,000 Reviews in Q3 2022.
Another keyboard solution is the Kinesis Freestyle2 Keyboard that has two separate panels--one for the left hand and one for the right hand. It is also available on Amazon with the ASIN number of B00CMALD3E for $89 as of August 2022 with over 1000 Ratings and 4.5 Stars. This specific model can separate the panels by Nine Inches. There is a $100 version with the ability to separate the panels by up to Twenty inches. Important: a numeric keypad for the Kinesis Freestyle2 is a separately sold device.