See that's what I don't get about people who know too much. Look you are right about doing it your way. Yes it can work, no it's not right. There are people on here who don't have an idea how to do anything, but try it themselves. We are arguing because on this site, we like the right way to be the knowledge that is posted.
Will the ignition timing fix the idle, I doubt it. Here is what I don't get, you say you've tried everything under the sun to fix it, yet we give a suggestion based on knowledge and not winging it, and you argue and say no that's not it. Well logically if you have tried everything, then maybe just maybe it could be the issue. You do realize that after messing with the timing and the BISS a whole bunch you may have multiple issues fighting you now?
I work as an auto tech and tune on cars out of my garage. Whenever I have a problem with something I KEEP IT SIMPLE first then go into the deep end. Seriously, you have yet to try to adjust the IGNITION timing THEN set your BISS. Now, remember if you do it the exact way that the original ENGINEERS who spent months designing these systems, you might get some answers. When you go and do it your way, it may work in some cases, but behold a "ghost".
I have never had a mitsubishi "ghost" issue. I keep it simple and to the books.
Like I said, here on this site if a newbie were to read this thread they might get the wrong idea. This is my concern. If your going to be on this site and your a "high end" tuner, then please remember that there are people who read these threads and learn from them. Like I said if you really have tried "everything under the sun", then what will it hurt if you set the timing and the BISS exactly like the repair manual states? I know you have your pride and your own way, but seriously, when your asking for help and then argue that the advice given is wrong without even trying it first, you'll lose all respect on this site in minutes.
No attacks at you as a tuner, I know SBR has built some quick cars, but remember there are people out there that want to be just like you and they will do it your way. You know what your doing and they don't, and for those people your way will fry their overboosted, under octaned, 160k mile engine.
Again this site is more about education than a huge ego powered cock fight.