Hi. Author of Next Generation Shell here. I had roughly the same motivation. The solution differs widely though. I noted that the main difference of NGS from other modern shells is the attention, prioritization and investment in the programming language. The language is now in a good shape and I'm starting to work on the UI. The first UI will be CLI.

https://github.com/ngs-lang/ngs

( For the curious, readme includes references to other alternative shells )