Do you have it on all your plans or is it on demand?
If it is on request, why not make a part of your ruler (possibly with configuration to adapt to the different scenarios: part of a few millimeters or frame of several meters) and insert a view of this ruler at the scale of the sheet?
"It's not stupid at all what you're saying there!" It happens to me sometimes... :-D
On a case..., I see..., I had to do it a few years ago for a client, I had first made a block of it, but with the risk of not scaling it up. The part solution was the most reliable, but if you have to provide the SW files natively, you have to provide the ruler.sldprt! With what it can cause in terms of problems with the coding of CAD files!!