You’re slightly on the wrong track, but I can help.
I play in a mid-core guild (haven’t even cleared SSC yet) but my P1-P2 logs for T4 content logs orbit within the top 50 world ranks for feral cat (depending on how hard I’m pushing that week or our kill time RNG).
https://i.imgur.com/fWC6Wve.png
Technically BB/Dragonspine Trophy is your BiS trinkets, but since the upgrade for DST over Hourglass is so small, most lists skip it so that you don’t waste the “loot karma” on getting one and instead let your hunters have it (or a class that benefits a lot more). Otherwise you should be using BB/Hourglass.
In a typical run through, your cat melee attacks are ~30% of your damage in addition to your rotation only being limited by your GCD as we are not limited by energy depletion (due to powershifting), so DST is very good especially if you get good proc RNG.
In P2, Tsunami Talisman/DST is again your BiS until you reach your 4p T5, in which DST gets outclassed by BB again. It (DST) stays strongly recommended for bear form, though, as a threat trinket.
You’re also thinking a bit too much about “the hit cap”.
For a feral cat, hit is weighted like any other stat and doesn’t have as drastic an effect simply by not being at “the hit cap”. It’s weighted less than agility, actually, although it is technically the strongest weighted 2ndary stat up until your cap. However, this means that when you look at items, you are still weighing it against the alternative, and sometimes, an item with hit could potentially be worse than an item without (usually the items that are without stats like str/agi etc). Sometimes, you may be slightly under hit cap, and you’re putting on a hit item to hit the cap, and all that extra hit over the cap is wasted, making that item a worse pick than a non-hit item with simply more offensive stats.
DFT is definitively worse than hourglass, though, in every single way. Regardless of it putting you below hit cap.
Also, do you have a boomkin? You should. If so, they should be using FF, reducing your global CD load slightly and making this a non-issue entirely since your “hit cap” becomes much lower.
Trust me, I’ve got DFT, Kiss of the Spider & Slayers Crest, all hanging in the bank so I have the options and I know how tough it was to “drop them” for the new stuff, but…that’s just DPS for you.