I have styles for Point 1, Point 2, Point 3, etc. (See this post.) It would be really nice if I could assign these to the keys 1, 2, 3. It doesn't appear to me they are being used for anything else.
I'd love to have shortcut keys to a small number of user-selected highlight styles. If they don't want to give away the 1, 2, 3 keys, then some currently unused combination of shift/alt/ctrl + 1, 2, 3 would be fine with me.
If you have an inclination to programming, you might be able to do a lot of things like this with Macro Express (www.macroexpress.com). The free version is hard to use but the pay version is easy (and powerful).
4.0c (currently still in beta) lets you assign letter keys (A-Z) to the highlight styles. That's fine for mnemonics like Y for yellow highlighting or whatever. I'm hoping the number keys can be added as options. Ctrl+<num> is taken already for GoTo Bookmark, and Ctrl+Shift+<num> for Set Bookmark. Shift+<num> doesn't appear to be used, nor Alt+<num>. I'd also welcome these additions if they were available.
I've got some keystroke macro software already but haven't used it in a while and can't remember what it is. Might look into that again or give Macro Express a try if mine proves not to be able to do this.
