You don't have to be a notified LARS unit to provide ATSOCAs. You have to apply and will only be nominated if there is funding available.
This is the whole stupidity of the LARS system.
We have non-LARS radar units that want to talk to people outside their ATZ (Cambridge / Oxford)
We have non-LARS non-radar units that want to talk to people outside their ATZ (Lydd)
We have non-LARS radar units that are typically too busy to provide a service to people outside their CAS (Stansted / Manchester / London Control)
We have non-LARS non-radar units that are typically too busy to provide a service to people outside their ATZ (Shoreham)
We have LARS units that want to talk to people outside their ATZ (Southend)
We have LARS units that are happy to provide a service to people outside their CAS (Norwich)
We have LARS units that want to talk to people for far too many miles away from their ATZ (Farnborough)
To solve this problem, every unit that can provide radar services in lower airspace (regardless of whether it is inside or outside controlled airspace) should be called LARS.
How it is funded is completely irrelevant to the pilot and his LARS charts.