Hello Superware,
of course its very hard for Israel Mappers to define city borders, as we are not even able to define the country border 
(just joking)
Actually I didn’t knew about the need of the is_in definition. But I will try to add it in the future.
Beside that, I have nothing against a automatic definition. Better than nothing.
I like the idea of getting all streets per city.
The next part should be to get the list of streets in a city by the government and compare that lists again each other and find out what streets are missing.