There is no placebo effect, only your mind self-deceives you by the name Fast (speed, without limit, extreme, etc) and when you read compatible you think: it is not complete, lag, slow, limited, etc.
My advice is trust the creator of the script and do not be fooled by the names.
@Sinner is right
and the fast version has a huge bug that does not exist in the compatible version.
Compatible > Fast (now it is no longer called compatible, it is called FreshJR_QOS)
and if you have lag I am 99.99% sure that the culprit is "Snapchat", because it is in "others" and that category is used for games or you do not have the "other" category, above the most, but below the category gaming and it's not because of the compatible version...
I do trust the creators, this is solely my opinion. I customized my script per instructions and put snapchat under 'web' vs other since i used the script for gaming. Like i said, never had issues with the fast script and the "bug" you mentioned has never been issue on my end.