We had that in the ranking a couple of years ago and I remember it being a giant pain as it really punished certain raid compositions and flawless for some encounters can contain a lot of RNG with who gets certain dets, etc.

It's fine if you want to include it in the scoring - I don't think it will change much as the folks in the top 5-10 are virtually the same In BoL where we tracked flawless for points and the current expac where we didn't.