That raises an interesting question: what would be the declarative framework easiest to minimally reimplement?

I’m thinking you could have a single file, jQuery-based, hand rolled version of some framework and get many of the benefits while still technically complying with the “no frameworks” rule. In the same way that you could reimplement Redux easily if you for some reason weren’t allowed to use it.

I suspect diffing performance would be the bottleneck but I wonder if you could come up with some weird half solution that worked for your particular use case.