I have about 150 entries in my User List, and 8 or 10 numeric levels.
Since I add new users with a mask of nick!*user@host, it can take
a little tweaking to get the user to match an entry every time.
If you are only using nicks, I can only imagine that the problem has to do with named,
rather than numeric levels.
To switch to all numeric levels you could make a script that would loop thru the userlist,
add the numeric level, then remove the named level.
It would be much simpler imo, to close mirc and open remote.ini in a text editor and carefully do a replace.
In either case you have to go thru your events by hand and change the levels accordingly.