So I'm testing Desktop Packager for the first time. Since my webapp will be updated frequently, and there's no Over-the-air updates yet, my app simply consists of the JS for toolbar etc, reading configuration, and a login form - which targets a remote URL.
Once logged in it downloads hundreds of JS files, images, css etc. (it just happens to not be minified/concatenated for testing). Looking at the debugger it starts off pretty quickly, but then slows to a crawl in making connections to downloads JS files.
Once the app is finally up (say 10 mins, versus a few seconds in Chrome), then navigation around the (extjs-based) app is very slow still. Of the order of 10-20x slower than expected.
I'll do some tests with the minified+concatenated version.

I'm guessing here that I'm hitting some performance bottleneck iin the framework due to the number or size of the resources I've remotely downloaded - perhaps the indexing and retrieval of files from the cache?
The actual process size is only ~60MB, so not astoonomical, and it's downloaded a few hundred resources totally <4MB.
Running the JS CPU profiler shows >98% of the time is not spent in the JS.
Is there any (undocumented) options to increase the size of hash-tables, number of concurrent connections it can make etc.?