When input the gap in Guide & Stopper in CII model phase

Dear Everyone.
I work in EPC company as an piping engineer.

I have a query when we input the gap in restraint such as Guides, Directional Stopper.
In EPC phase, contractor's standard pipe support usually have 3mm gaps in Guide & Stopper. Thus, I thought in CII modeling resraints will also have the same 3mm gap but it did not.
I have discussed with my senior engineer, but he could not gave any answer to me why we do not input the gap in CII. He said it was based on customs.
Does anybody have the reason why we do not input the gap in CII modeling?

3mm gap as standard may be there or may be not.
In addition to this uncertainty, these gaps can be a source of non-convergence for calculation.
IMO, you should consider a gap when you are sure it is in place. To be sure it is there, you may mark the value on isometric asking to be checked in field.