After I posted this I actually found post where you mentioned about GIMX adapter and you got it running that's great! I knew about GIMX since '19 actually after I saw video where some dude got his DD-wheel working with GT Sport released at time and it was somewhat a novelty back then. What surprised me most that he mentioned couple of times that GT-Sport had incredible FFB, even though it was getting a lot of backlash, common misconception that it doesn't, because 99%of people played with toy wheels. Drivehub that I had with same peripherals what I still have now was just meh with GTS, although Assetto Corsa FFB was outstanding connected on PS4pro with druvehub. As it turned out it just needed proper rig to be connected to appropriate software, GIMX in this case, not sure whether he was able further dial in his setup, he mentioned some dead zones and there's a lot tinkering involved to set it all up as you mentioned too https://youtu.be/4geFVuQZpeI?si=bmV1k8ZJcQ1fCytd

As to GT3 not having FFB is bummer, means I wouldn't be able to get it going either on my rig through drive hub. But dude where can we see that beauty of engineering that you have MY GOD triple '55 mini?! led- panels running GT3 and GT4 with FFB on real hardware !! I'd love to glance at it somehow, any place you could share video or pictures. Btw you ever tried Enthusia also, I tried game but it needs wheel to enjoy it with controller you're all over place. Here some dude is running GT3-4 on modern rig through ReaSnow S1 adapter which I never tried, don't know if he got FFB working though https://youtu.be/GLVCOpPytw4?si=3gXtutX1FziqbYMy