No, I haven't gone the MultiBeast route, at least not yet. Right now I'm back to 'square one' after discovering motherboard hardware problems completely unrelated to OS X or creating a Hackintosh. A board replacement with fresh install of Win7 looks like what I need to do first, then return to creation of Clover + Yosemite install stick.
I posted the query because I came across a help request (on another forum) in which the OP had installed OS X using Clover, on similar generation hardware to mine, but could only boot into OS X with the USB installer still connected, but did not as yet find a resolution. In my past hours of research across multiple forums, I'd also seen repeated instances of users having the same boot issue, so I began to wonder if there was a 'most likely' configuration error(s) resulting in the problem. This is on Intel 9-Series + Haswell hardware, so current stuff.
If the list of potential causes of the problem is too long, then fair enough. I'll take my chances later on if I can get my box re-built and working optimally in Win7 like it should be.