Extra RT for 120.4 as a start.
Every aircraft would have to be told of the alt restriction (if on the LLZ/DME)
(unless the kind SVFR controller would "give" the airspace to FIN - and guranteeing no aircraft below the final approach track)
If the helilanes were quiet then it would be fairly easy. The only other extra RT would be to tell the aircraft on the LLZ/DME the type of approach with the landing runway, and you just say "descend with the procedure" when established.