I think your suggestion is good to have, that's why I've created Pits item for it, so you may vote for it.
About the TreeListView - we'll consider what can be split in a way that will allow better minification.
The "Xap Minifier" is ready to go (it is testing phase) and will be published and officially announced in a week or two. Hope you'll try it once it is available and give us your valuable feedback.
the Telerik team
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Public Issue Tracking
system and vote to affect the priority of the items