From the Panic blog:

Even if it were viable, we’d likely run afoul of App Store policy as well. Apps on iOS and iPadOS must use Apple’s Javascript interpreter, JavaScriptCore. Although JavaScriptCore is excellent, many developer tools rely on features or behaviors only present in Google’s V8 JavaScript interpreter. Similarly, WebKit is the only allowed web rendering engine on iOS.

And still, even if we could find some clever technical way around all of these limitations, we wouldn’t know if our approaches would be allowed on the App Store until we’d fully built and submitted them for review. So, we’d be facing a huge investment of time with the possibility that it would all ultimately get rejected.

It really does pain me to see a developer want to make a great, professional app for the iPad, but can’t do it because the OS simply blocks them from doing what they (and their users) need. It’s doubly painful to hear them say that they could maybe find some clever workarounds to make it work, but then are worried that they’d be blocked from distribution on the App Store.