These sound like fantastic changes--I seem to be having issues getting this version of the file to work, however. I have the plugin in the same order placement as the prior version, which worked OK for reference.
Trying to switch with the default shift hotkey isn't doing anything, Edit: Got it to toggle again by removing the plugin and re-adding it fresh. Not sure why that made a difference, but it did.
A weapon that I have with the <TWOHANDED> tag set as its default grip is printing the <ONEHANDED HELP TEXT> in its description block. On further checking, it just seems to ignore the <TWOHANDED> tag in general and defaults to one-handed for stats + the help text blocks.
I'll try tweaking my plugin order and other troubleshooting, but figured I ought to report in just in case. I have this plugin towards the very bottom of my list currently.