Techs normally have to anticipate the amount of "set" a new low pressure seat (in the second stage" will take as the seating groove develops. This is the most common problem that you may see with a newly servcied reg.
If the reg is tuned for minimum cracking effort and the tech under compensates for the seating effect, a slight freeflow will develop after a few to several dives. It is an easy adjustment to fix the problem and a tech can take care of it in about 2 minutes. but it means a trip back to the LDS and it can be a pain for a diver who takes the newly serviced reg on a week long die trip.
So consequently, many if not most techs crank the inhaltion effort up more than is needed to ensure no freeflow will result once the seat is broken in. Customers oddly enough complain a lot less about a harder breathing reg than they do about having to come back in for an adjustment on a finely tuned reg. This is especially true if the customers ship their regs somehere for service, and where runnig down to the shop for a follow up adjustment is not an option.
If they do complain, many shops then convince them they need to upgrade the reg and will sell them a more expensive model, often with a diver adjustable cracking effort knob where the diver can resolve any break in related freeflow issues themselves. The diver adjustment knob is a nice feature in this regard and it does allow the tech to tune the reg for max performance with no worry of an unhappy customer coming back for a retuning of the reg.
There is a machine available that will rapidly cycel the reg and speed the break in process, but they are still not all that common.
In general though, you should get your reg serviced well in advance of a trip as letting it set a few weeks has the same effect on the LP seat in most regs as does doing a few dives and then either dive the reg prior to the trip or at least hook it up and check for any freeflow.
If it has been several months since your last service and you want to ensure the reg works properly prior to a trip, you can take it in for a flow test where the shop can confirm the IP is stable, that the reg is properly adjusted and that nothing leaks. Then you can get an annual service done after the trip.
In any case, there is no excuse for IP creep on a freshly serviced reg. Checking for proper and stable IP is one thing that is done as soon as the first stage is assembled and prior to any adjustment of the second stages. If you have IP creep on a newly serviced reg, the tech skipped a step.