Tried some alternative parts to increase the amount of exposed rubber, reduce the amount of material used & allow them to be installed after lacing.  Besides taking a lot longer to fabricate, the heel change made no difference in the amount of material consumed & they can't be installed after lacing anyways.  The toe change was still effective & there was definitely less feeling of running on plastic.

Tried polyolefin craft cord without getting any improvement in the chafing.  Bedrock Cairn's seem to have the key to 100 mile range & they're now in retail.