The core functionality should work when using the classic template.

The devel template probably has a bit more JS usage (I haven't
checked in detail), but even there most things should work.

The only things that do not work are the (cal), (list) and (help) links
next to some attributes (you would have to manually enter correct
values or open the links in a new tab/window and after looking up
values copy them back to the original window), and the automatic
generation of a suggestion for a username based on the real name when
adding a user account (which I consider very unimportant and sometimes
even annoying :))


The responsive or jinja2 templates will probably not look good
without javascript, but I haven't tried.