mlhetland
commented
2 years ago Several things going on, here. For one thing, local variables like \l_tmpa_tl and \l_tmpa_int were not zeroed out at the beginning of the scope, and so they're getting polluted, now. For another, the call to \keys_set:nn with \only occurs inside a group, and so they disappear as soon as the unknown handling is done. We would probably want to keep that group for handling the local variables, but we need to get the key-setting exported. Already using the trick of using \exp_args with \group_end; I guess that could be extended – but we'd only want anything to happen if we've actually called \keys_set:nn.
It seems in that, currently,
\\<1>– which is tested in the docs – works, but\\[hl<1>](and the like) does not.