I agree zones, using letters in the vertical and numbers in the horizontal are the way to go. Simply refer to the 1.53mm dimension in zone B5 when identifying the specific dimension in question. I've worked with some very complex multi-sheet assemblies that effectively used this and save a bunch of time. The only time I would ever consider giving a specific identifier to a dimension would be if it was highly critical and very confusing. Even then I'd be VERY reluctant.