This is the basic unit of this build. Since both products and resources in the process are the same, they are send to another centrifuge. BUT - with each cycle there is fewer dark uranium, so from time to time it will be resupplied by bots, therefore there's a requester chest inbetween for it. Meanwhile, amount of bright uranium will increase, therefore it needs overflow buffer. Currently it's just reading steel chest content and removing it away to active provider above certain threshold (currently set to 40, but didn't test it throughly yet). It may be possible to replace both it with just buffer chest but tbh I didn't yet get a hang how they work. Now, what do we do with it?
We chain those units in circle. Now big amount of produced resources that's usually put on belts or picked by bots just to get back to centrifuge a moment later will be reduced to minimum, because they stay in closed cycle. It's even somewhat beaconable, but you need to be careful to keep each centrifuge at the same speed. Of course it needs to be primed manually, then you can forget about it.
Also, the same idea can be used for belts, there's just more circuitry to do - each inserter is linked to own chest, for dark uranium it's load more if it falls below, lets say 10 and for bright uranium it's unload only if it's above, lets say 50 (and better set it to single stack bonus):
