4 digits is too many UX wise - should be 3 digits.
However, depending on how VTP integrates NIST EDF's (which is a big TBD), it may be the case that as more precinct adopt VTP, the contest UID's will still want to be globally unique. At the moment that is accomplished by the 'requirement' that any precinct running with VTP needs to know about any other precinct also using VTP for a contest that is tallied across the precincts. The requirement can be relaxed with a decrease in UX (in that the UID's now become big random numbers as opposed to being short and sort-able 4 digit numbers).
4 digits is too many UX wise - should be 3 digits.
However, depending on how VTP integrates NIST EDF's (which is a big TBD), it may be the case that as more precinct adopt VTP, the contest UID's will still want to be globally unique. At the moment that is accomplished by the 'requirement' that any precinct running with VTP needs to know about any other precinct also using VTP for a contest that is tallied across the precincts. The requirement can be relaxed with a decrease in UX (in that the UID's now become big random numbers as opposed to being short and sort-able 4 digit numbers).