I guess you already know this, but there's a problem with the belt speeds, specifically those speeds above 30 items/s.

Right now, the miniloaders insert items at 10800º/s, meaning 30items/s, meaning no matter the tier of the belts (specifically bob's belts and ultimate belts, those compatible with your mod), items will never go faster than that.

Could there be a way to increase that rotation speed to adjust it to the belt speed? (for the last tier of UBelts it should be 1.62e5º/s, which might be a bit excesive, but for the last tier of bob's belts it should be 6.48e4º/s, dont know if thats possible, but at least its not as much as the other)

Ok, now something weir happens, I have both Ultimate belts mod and Bob's logistics mod (bob's belts), with UBelts, 24 loaders to a single warehouse produced 43k/min (43200/min is the max rate with the 10800º/s inserters speed). Since speeds over 30items/s had no effect, I changed all belts and loaders to last bobs tier (180 items/s, still over 30), but now the rate with those 24 loaders to a warehouse is 21k/min, like half the previous, this shouldn't be

Ok, forget all about this, I did the math the wrong way

Ok, do ignore all above messages, however there is an actual problem with ultimate belts, doing the math (the right way this time), 24 full UBelts (450items/s) should deliver 54000items in 5 seconds, but the maximum amount that they deliver is ~43k, which is ~518k/min, which corresponds to ~360items/s per belt