Thanks for posting updates about this brew.
I love Rochefort-10 and have seen a few different recipes online.
(Have you seen the recipe on the CandiSyrup.inc website?)
I tried doing a quad last year after reading this thread.
But I ended up doing the Belgian Quad from James Morton's book.
I scaled it down and just did a 5L stove top version.
It all went ok, despite no temperature control.
The brew didn't turn out as dark as I was expecting, and some of the bottles weren't carbonated. Maybe because I didn't add fresh yeast at bottling? It tastes OK. Quite nice really. Definitely doesn't feel like I'm drinking a 10%+ beer. But it IS strong: I fell up the stairs after having a 330ml bottle last night!
But it is definitely nowhere near the complexity and smoothness of a Rochefort-10. I guess I'm kidding myself if I think I can get anywhere near that though.
I'm going to have a re-read of your thread and have a think about what to change next time I brew this.