Hi,
it seems that extjs.cachefly.net also works over HTTPS, and so using extjs2 from there is also an option - actually could be the default option - even when serving the page over HTTPS. (The alternative is to download extjs2 and set up the local webserver to serve it over HTTPS.)
See my GitHub pull request here: https://github.com/ollyg/Catalyst-Plugin-AutoCRUD/pull/29
norbi