[leeoniya]

i'm not sure i follow your logic. how does a poor data connection affect js execution?

if you have to do additional template fetching via follow-up async requests, sure. but if you serve the js & js-parsed/executed template in the initial request, then the only difference would be a synchronous reflow/paint for js (white page flash) vs streamed/incremental reflow/repaint.

[izym]

If you can barely get 1 request through, it might take a long time before the JS will load and run, as it has to load completely before running at all.

[dbbk]

A poor data connection would affect the js download, not the execution per se.