Unfortunately, yes, that's an issue.
The user ID must be a 32bit unsigned integer on a POSIX system. I don't
see any attribute with the user entry that could be (ab)used as a user
ID, sorry. I'm afraid one would need to be added on the LDAP side..
I'm sad about that :(
Is there a way to remove the leading 'P' that is leading in the 'uid'
attribute so I can use the numeric value?