Handy Utility Belts to make working with belts a little more compact or cleaner. Includes a lane balancer and lane swapper in all the base game speeds.
So looking at the Krastario, probably be fastest for me to add since I mainly would have to just recolor the graphics for the structures I already made, and some other smaller adjustments.
Space exploration probably, will be a bit later since it looks like graphically there are more unique and all those color variants with glow too. Both have been added to my todo.
For SE, you can look at the K2 loaders. K2 added "just" 2 loaders to support SE belts. One white one for the space belt and a black one for all the colored ones. There is some logic in SE provided that K2 uses to dynamically change the belt color of the loader. This would be the best approach, since a balancer and swapper for each color of same speed belt would clutter the inventory/recipe window. Also, this way your mod would be more consistent with other loader mods that work this way (K2 Loader & Miniloader mod). Hope this can help :D