This is really exciting! Many popular Rust libraries support switching between rustls and openssl for their TLS needs and it’s much easier to do cross-platform builds with rustls.
Key chatter means you press the key once and it outputs several presses. In my case it didn't happen consistently, so was incredibly annoying.
I'd estimate ~3 weeks of very regular practice to get up to my previous typing speeds on the TECK or Ergodox. However before that I'd also learned to use the Kinesis Advantage, Freestyle, and even the FingerWorks TouchStream (http://www.ergocanada.com/products/keyboards/fingerworks_lp....)
I used the original Truly Ergonomic (TECK) for several years and really liked it overall. However of the three I bought, two had serious key chatter issues and it's very difficult to get any support. The company has a really poor reputation as demonstrated by many threads on Geekhack (https://geekhack.org/index.php?topic=89035.0)
I switched to the Ergodox (currently Infinity model) and am very satisfied, but they can be a little difficult to source. Hopefully this new model is a viable alternative.