@Jim-Hall: That MS Natural is the second-gen with the broken arrow-key layout and just-wrong 2x3 six nav keys. The "original" Natural had proper inverted-T arrow keys and the nav keys in proper 3x2 layout.
I had one of the original Naturals and it was fantastic. Rapidly accelerated my typing speed, and - most curiously - made me even faster on regular keyboards. Unfortunately it was rubber domes over capacitive sensors and eventually just wore out. IIRC the P and I keys wouldn't respond reliably after 5-6 years.
I spent several years wandering in the desert of crap keyboards after Microsoft abandoned the proper Natuaral until the mechanical key revolution finally caught up with me.
I went through a couple Cherry MX Brown keyboards - Rosewill and Logitech G710+, which are very good - before rediscovering the joy of clicky "blue" keys. My current favorite is a tenkeyless "Hcman" H01 keyboard I picked-up at Goodwill for $6 on a whim! It has "blue" clicky keys with great response.
I think a lot of avoiding RSI is posture, typing form, and paying attention to your body. I've been typing all-day every-day for more than 35 years (data analyst/tech writer) and have managed to avoid any signs of RSI. I've been extremely careful from the beginning to keeps my wrists straight and fingers as relaxed as possible when not hitting keys. Fortunately, it's worked so far.
Nifty. Never heard of this before. Already installed on my system. Thank you!