I don't want to put words in anyone mouth, but I'll speculate on this a little...
I would bet Aware is looking for EXTJS 4.x to deliver these features are currently uses 3.x which has flash charting. 4.x is all JS based. Unfortunately, in the current state EXTJS 4 is slow as $*!^.
I had some custom features built for better charting a few months ago, and Aware spent a lot of time prepping to move to 4 as part of that process, but my features are stuck until the framework performance improves. EXTJS 4.1 was supposed to fix the issues but it's release has slid by months, it is now in beta.