Unfortunately the project looks pretty dead. And further one of the bullet points is "is lightweight: ~2000 lines of source code (excluding libraries)" but looking into app.js it's something like 23k loc. It uses react but it looks to be pre-JSX. And because it's all in one giant file it feels too overwhelming for me to want to learn/extend it. He says it's compatible with IE 11. And maybe that's why it's structured that way, but I don't know. Despite it all the idea is really cool.
Mesh's backend sits in one giant file because that's how we can write it in a Mesh sheet. But unfortunately the JS parsing library is huge and forms the bulk of the code. Happily, the k version is currently ~100 lines excluding tests.
If JSX were used, would the code need to be compiled? Mesh used to have a compilation step but it just added complexity (config files, build process, increased download size). Keep it simple! React.createElement is fine.
I've never seen k, nor any array langs before but would definitely checkout the K mesh version.
No idea about the JSX though.