5) With KFMIRL, we're essentially adjusting how early and aggressively boost comes in, correct?

5) No, I don't think that's the intent. You are describing the use of LDRXN, but KFMIRL can have side effects if you change it. Unfortunately there is a lot written about KFMIRL / KFMIOP on here that is either not right or right for the wrong reasons. I think the S4 wiki has some updated stuff on this. They are translators or conversion tables. We are mostly changing the resolution to make it have detail where we need it and to change the range if the new tune asks for parameters that are out of range on the initial tune. (You are still preoccupied with boost.)