I was interested to see that this uses the DukPy wrapper around Duktape for the JavaScript interpreter: https://browser.engineering/scripts.html
This made me start digging into whether this was considered a "safe" way of executing untrusted JavaScript in a sandbox.
It's not completely clear to me if DukPy currently attempts safe evaluation - it's missing options for setting time or memory limits on executed code for example: https://github.com/amol-/dukpy
There's a QuickJS Python wrapper here which offers those limits: https://github.com/PetterS/quickjs
I'm pretty paranoid though any time it comes to security and dependencies written in C, so I'd love to see a Python wrapper around a JavaScript engine that has safe sandbox execution as a key goal plus an extensive track record to back it up!