My HED setup for the Demon 98
Coupler = Av-Bay
Shock cord attached directly to nosecone tip
Tied a loop about 3/4 inches outside of nosecone to attach parachute
About 5/6 feet of shock cord, attach Nomex
Remaining shock cord goes to av-bay bulkplate.
For the Demon, I use a Recon 40 as main and the shock cord is 1/4" Kevlar. I use a OBH harness in the booster side just cause I like it and had a spare lying around, though I used a Nylon one for the original build and first couple flights. the 1/4" Kevlar has been in from the start.
When I pack the nose, I z-fold the shock cord and place it in the tip of the nosecone with the chute after. So, the chute bundle ends up right on the bulkplate. I use centrifuge tubes for my charges, and I just put them right on the bulkplate, no need to get them in the tip of the nosecone since the shock cord will pull the chute out not matter what. I've lost count of how many HED deployments I've done this way and never had a problem. Some tips that I try to keep in mind, I always wrap the chute bundle tightly so it's not "stuffed" into the nosecone, more of a loose fit. Then, most of the shock cord being in the tip of the nosecone pulls the bundle out. Not sure it really makes a difference, but since it's worked perfectly thus far, I'm not changing it.
For the 4" Polycarb nosecone on the Demon, I've been using 1.5g and 2.0g charges in the nosecone. I think I used a 1.0g charge during testing and it worked fine, but only popped about 3 feet. the 1.5g pulled out about 10 feet or so, 2.0g as backup. Keep in mind, my 2.0 centrifuge tubes are probably more like a 1.8 actual charge since the e-match head takes up space along with the putty.
Hope that's clear as mud. If you want, I can post pics.