Wildcard / RegEx support for autofill form ids

Some login forms use random values for username or password id (and no label), therefore it is impossible to use the autofill feature.
A workaround would be to use a macro, but this works only like 50% of the time. eg: page takes too long to load -> macro is executed before the form is even there, session losses focus for whatever reason -> keystrokes are send into the void ...
And if it's the password field, it's no longer possible to make the password invisible to lower privileged users.

It would be great to be able to use wildcards like username* to match those random ids.
RegEx would be better to narrow down the results, like to a fixed string followed by 9 digits: ^username\d{9}$. But this might be too complex for many users.