Persistence and Duration

So I've noticed that Durability on the Stand Stats have been chaged to be Persistence, where it deals with the "duration of time that the Stand can be kept active and maintain its ability." There's just a few issues I have with this.

First, let's compare Star Platinum and King Crimson. King Crimson has an E in its persistence despite having been active during its entire introduction to "hide" Diavolo, but its time skip is also 10 seconds long. But then you look at Star Platinum, which is rarely ever summoned for that long but then you have the added bonus of its time stop being 5 seconds at max. How is SP, a Stand with a lot less feats to support being an A, be above KC, which has shown several times to be worthy of A but has an E.

These two aren't the only Stands with this issue. Tower of Gray and Cream are both Stands that, like King Crimson, are active their entire arcs, yet they have C. Compare it to SP, who was in the ToG arc, and it had lasted much longer. Or even Goo Goo Dolls which has an D despite its ability having effected Jolyne for its entire arc. There are several other Stands with this issue like Under World and Mandom that equal or are even higher than the likes of SP in duration, yet have stats lower than an A.

There are also contradictions within some Stands themselves. Star Platinum: The World is a large one. Part 4's SP:TW has a time stop of 2 seconds at most during the part. But then you look at SP:TW in part 6 and you see it has its full 5 seconds, yet has an E in persistence. In both parts the Stand was used around the same amount of duration, with part 4 probably having slightly longer sessions, but that wouldn't be enough for an A.

In conclusion, I think persistence should just go back to being how durable a Stand is as that is much more constitent than what persistence is describing a Stand to be now. (Also, does the new definition of persistence have a source to have it be the way it is?)