This is very interesting, and definitely a safety hazard.
When I am issued a SID by clearance delivery, I am given 6000. I readback 6000 to clearance delivery. When I get airborne, I readback 6000 to departures as it is my cleared altitude, even though the SID has stop off points. These form part of my clearance which I read back to clearance delivery, and I am required to comply.
Now you say I must read back the stop off points as well? Do I also advise when I have left them after maintaining for a short time. Where does it stop?
I think the problem here is with the SID design. SIDs are supposedly designed to reduce workload/RTF etc. Seems to me that the SID in question should be issued with 4000 or 5000 or whatever is required for separation assurance, not develop a local procedure regarding read back requirements.
Fly safe now.