One could ask why identify and verify VFR flights on FIS?
How about FIS being a common service regardless of unit be it Area FIS, APP or LARS. Perhaps then pilots would understand it a bit better and not expect more than they get.
However, as I undestand the rules 7000 can not be used to establish identity and consequently the level can not be verified.
There is nothing in the rules however that prevent you using primary radar techniques to identify an aircraft that is on a 7000.
If however, a LARS unit gave all the VFR flights a single
assigned code then everyone knows that they are in contact with.
The whole idea is simply to leave more codes available for aircraft getting or more appropriately, needing a radar service.
Regards,
DFC