TCL is an interesting idea. I have been a fan of MicroPython (https://micropython.org/) for a while. It's probably not as tight or efficient as Partcl but I think it may be a good contender for a comparison in your original article.
I was about to suggest the same; Micropython requires a little more flash/RAM (https://github.com/micropython/micropython/wiki/FAQ) than the authors goals but it's certainly no toy language despite the immature (but rapidly improving) tooling and libraries. I'm pushing to use it in more of my embedded projects - and have little desire to return to embedded C!
MicroPython also has an ESA sponsored port for their space hardened architecture and RTOS. And even more impressive, I'm writing my thesis about evaluating MicroPython for CubeSats.