He probably ment to cold blue the back of the trigger. The triggers are blued on those arent they?Did he say he would polish out the scratches in the stainless?If the ridges are taken off the back of the trigger and the trigger guard repolished that should cure the problem.Cold blue on the back of the trigger would not have any wear on it and should not wear off.
If i understand correctly the trigger which is blued has a ridge on the back being a mim type and it is scratching the inside of the trigger guard.
Smith and wesson repair guy said he would polish of the ridges on the trigger and cold blue it.I would assume he wasnt talking about the stainless steel trigger guard being cold blued.But he could polish the scrtches out of the stainless and well as the back of the trigger.Since nothing touches the back of a trigger I would assume the cold blue would not wear off.
The whole deal sounds like something the man should not have to deal with at all though.
Its a manufactury defect and a patch up job actualy .But seems like it would be un noticed if the repairman polished up ever thing etc.