Earlier quoted context omitted.
which is not allowed on iOS ... Edit: Sorry for being unclear, was only referring to the updating JS on the fly and circumventing App Store part. Obviously (facepalm) ... ️
Which part isn't allowed? A project I worked on did this a few years ago.
2.5.2 "Apps should be self-contained in their bundles, and may not read or write data outside the designated container area, nor may they download, install, or execute code which introduces or changes features or functionality of the app, including other apps."
and
4.7 " your app must use WebKit and JavaScript Core to run third-party software and should not attempt to extend or expose native platform APIs to third-party software"