[cisco-voip] extensions starting with 0

[IT]

We are about to add a branch office with extensions that are 02XX.  They
currently use 3-digit extensions, on a PBX. We will be putting them on
our callmanager with a 2801 onsite. The current dilemma is whether to
let them keep 3 digit extensions? This may be a problem since we
currently use 4-digits and we have extensions that begin with 2, so the
interdigit timeout could be a problem.
The other option is to go with a 4-digit extension and start with a 0. I
guess the problem will be our current translation pattern that passes
people who dial 0 to the operator. I don't think many people use this
feature, so it wouldn't be too much of a problem to turn off. Is there
any other issue with using extensions that begin with zero that I may be
overlooking?

Thank you,
Avidan