I think it would be handy if the "download only" button would allow you to download an extension and all of its dependencies even if it's already installed. Often I find myself in the situation where I'd like to get the wireless extensions, or opera, or whatever via the appbrowser on one tc machine and copy them via sneakernet to another tc machine that doesn't have an internet connection (I haven't had any luck just copying the installed tce's from the running machine -- iwconfig for example always says its missing a library even though I copied all the tce's from the running tc machine). If the "download only" button worked even if the extension is installed on the host machine, I could be sure that I've copied the extension and all of its dependencies from "optional" without having to guess what belongs to what (or have to go look up every dependency for an extension).
Just a thought.
Thanks.