Option #2: In [F]ind -> ser mode, when manually entering the User ID in the "By Address" field, could the Users List automatically scroll to narrow down the location of that specific User ID as it was typed in? For instance, typing the first character would cause the User List to start with the first ID starting with that character, then with the second it would show the first ID starting with the two entered characters... etc.
For example, if I were to manually type in User ID "32DC", as I typed 3 the User List would scroll to the first ID in my list beginning with 3 which is "3073", as I typed in 2 the user list would jump to the first ID starting with the combination 32, which is "3200", as I typed in D the User List would scroll to the first ID starting with the combination 32D, which is "32D0", and as I finally typed my last character C, it would scroll to my desired radio ID in the list.