I am not completely familiar with the original clone recipe, but I would advise not adding honey directly to boiling hot wort. To preserve some of the aromatic properties of the honey, add it when the wort is below 100 F. Ray Daniels describes how to add honey to beer in his book, Designing Great Beers. Honey is sterile, but some people choose to make sure by holding it at a low temp. for a certain amount of time. And I would shoot for 15% total honey instead of 12%.
At only 60-ish IBUs and tons of hop aroma, presumably from late hopbursting and dryhopping, I would think the first bittering addition is much lower. A 20 minute addition probably doesn't exist.
Lastly, pitching a yeast starter of the appropriate yeast into highly oxygenated wort, following the proper fermentation temperatures, and giving a little more time than usual for conditioning are all of the utmost importance for a big beer like this. So make sure you're using enough healthy yeast and your temps. are on target. I would have personally made a starter with liquid yeast and brewed a full 5.5 gallons. This is a lot of work for an excellent clone of only 2.5 gallons. It will only give you about 4 six-packs and be gone in no time.