There's a discovery that Tesla uses OSM for Smart Summon:
OpenStreetMaps and Smart Summon
So in theory, if you create a new private street, you should be able to perform summon there but I haven't heard any successful report yet.
It is also assumed that Tesla speed limit must also come from OSM but I have not heard any admission from Tesla yet.
Tesla may use OSM and anyone can enter erroneous info so I guess Tesla still has to verify the data for validity.
That means you might as well send a corrected speed to Tesla directly rather than through OSM.
My guess is Tesla is pushing toward speed sign recognition rather than manual speed inputs.