To say that "Helicopter IFR procedures simply do not exist" isn't exactly correct.
There are plenty of Copter Rnav procedures that has nothing at all to do with borrowing airplane procedures.
Here's an example:
COPTER RNAV (GPS) 190 to Southampton Heliport (87N)
I certainly think we need more helicopter IFR procedures, and more support from ATC, there's very little accommodation for helicopters in the system. An example, again, is 87N. There's a time limit on the pad, and no departure procedure at all. So whilst we can get in, we can't always get out. And taking off without a release, even with a flight plan on file, is to chance an "unable" reply from TRACON.