BTW, there has not been a compelling argument for making I_L in type-2 depend on Kpar either. IMO this just closes a door, is completely unnecessary, and even complicates reasoning about the security of the whole scheme.
I offered you some arguments with regard to reduced security and privacy in post #218, and Pieter and I mentioned that you'd feed less than optimal entropy into the hash function (e.g. you'd repeatedly feed 256 pseudorandom bits to derive the next 512 pseudorandom bits, instead of 512-->512 as in BIP32). One reason why you might not find the entropy argument compelling is that you don't spell out your exact proposal on how to do type-2 and type-1 derivations. I'm not sure if you think that the chaincode should depend on the parent privkey with type-1 derivation.