It would be nice if there was more support for tab in the application. Currently in most places tab does not work as expected (such as adding a new notebook, tabbing seems to invisibly move across fields) or is unsupported entirely. Even when using tab when creating a new note, the order moves from to the title to the body to to and starts over again.
I haven't gone through every section of the app but in general there probably should just be a clearer logical ordering for tabs and a clearer focus highlight everywhere.
For example when editing notes it'd probably be cleanest to have tab simply cycle between the title and body only, since tags have to be manually entered in a dialog. It would be nice if there were more clear focus on these elements too, such as an outline on the input.
Another example (and a bug): When adding new notebooks there is no visual cue what the tab focus currently is. There is also a bug where if you create a new notebook, type a name, then press tab (presumably focuses "Select emoji..."), then tab again (presumably focuses "Select file..."), then tab again (presumably focuses the "OK" button), if you press enter at this point, TWO new notebooks of the same name are created.
Lastly, tab does seem to cycle through the options/settings but it's rather subtle and again could benefit from a highlight on those fields. This just helps people who are more keyboard focused or use screen readers.
Thanks 
https:// accessibility.digital .gov/ux/tab-order/
https:// accessibility.digital .gov/ux/focus/
Windows 10
Joplin 2.7.13