Just a note:
I hope you will consider not removing certain functions from the plugin as it is when you phase-in the new modules.
One thing that sticks out in my mind at the moment is that the new CSS module differs in that the option to load CSS in the footer is no longer available, replaced with timed delay.
The problem with this is that not all browsers process DOM manipulation the same way or follow the instruction to delay parsing the same way, whereas all browsers do in fact process CSS loaded in the footer the same way. It seems clear that the option to load CSS in the footer was removed from the new CSS module since timed delay and load-in-footer should — in theory — be capable of producing the same results in the wild. They do not.
Short version: It would be great if you would keep all of the current functionality available plugin-wide and add the new features on top of an already great schema.
Super short version: Don’t fix what ain’t broken! ??
Be well,
AJ