It's interesting that you suggest the OS should recognize it as a 2P 4 core rather than 8 core.
I hope by the time Ryzen 5 releases many of these issues are ironed out by motherboard manufacturers and RAM manufacturers. So far the only RAM company seemingly on top of the RAM issue is GSkill , their "solution" in the long term is to release AMD Ryzen specialized RAM in the form of Flare X.
If your reasoning is correct then the biggest improvement could come with greater support RAM speeds (due to the CCX's Infinity Fabric implementation). Earlier news suggested the Infinity Fabric would be faster : "The company declined to give data rates or latency figures for Infinity, which comes only in a coherent version. However, it said that it is modular and will scale from 30- to 50-GBytes/second versions for notebooks to 512 Gbytes/s and beyond for Vega." http://www.eetimes.com/document.asp?doc_id=1330981&page_number=2
IMO when you see Firestrike/Timespy benchmarks with the Ryzen 7 competitive with respect to i7-6900K & i7-7700k @5.1GHz, then that means it is a game optimization issue.
Also I realized the Stilt's reasoning of < 3.3GHz being optimal for these chips might mean we ought to be under-volting instead of overclocking. It certainly explains the clockrates on ryzen 7 1700 and Ryzen 7 1700X.