I'm not exactly understanding why someone with what they think is a brilliant idea would first seek affirmation of the brilliance of the idea from a bunch of strangers on a web forum, and then get pissy about a response that basically tells the truth, which is it's not a very good idea. And the fact that not one soul on this entire site has come back to answer the question "has anyone else done this" should tell the OP something.
If you are so unsure of your idea that you need some stranger to tell you it's OK to do it, I'd submit you already know the real answer, and that would be to forget modifying the stock tensioner and buy something that was actually designed by someone with the engineering knowledge necessary to do it right. If you don't want a Hayden, just leave the stock one in place or get a manual adjuster. Manual adjusters worked fine on the '06 and earlier bikes. Of course you'll need to remove the outer primary cover to make any adjustment, but it isn't necessary all that often after the initial break-in of the chain and sprockets. But by all means, go ahead and butcher your stock part if you want, then go back later and fix the damage plus buy a new tensioner. It's only time and money.
If you're looking for a sugar coated response, I'm the wrong guy for that. Sorry.
Jerry