Best practices for slab-on-grade slab penetrations

[ChiefTesoroTX]

I'm about to start marking up all of the drainpipe slab penetrations in a slab-on-grade plan.  I couldn't find anything at all showing how others have approached this and I'm looking for a good approach.  My thought was to use either a Point Marker  or "BMW" marker  and then set up a special Dimension layer with dimensions attached to these, to show measurements from the edges of the slab forms so that the PVC can be placed precisely when the forms go up.  Am I thinking about this correctly?

[amddrafting]

We use point markers and dimesion them to the slab edge.  We add a label for the fixture and room name