Is indeed something I want to look in to, but currently I lack time to try and work this out.
As I use Bob's mods (which adds belt tiers too), I'm willing to research possibilities, but it'll probably have to wait till summer holidays...
I added 2 more beltSorter tiers which are activated if either bobs or ultimatebelts is active, supporting 60 and 75 Items/s. If I find more time I can add additional ones for ultimateBelts, but for now you can just use multiple (bobs) Ultimate BeltSorters with 75Items/s that should help a bit :)
It would be really useful as my current base uses weird constructions of 3 splitters and 4 sorters to split the cyan belts. Hopefully this will get added in the future :D