It feels like the Corporea Retainer should allow me to build a system where I can request any number of items from a Corporea Index and have that exact number of items delivered to me, with items being auto-crafted as needed. Unless I'm mistaken, that's currently not (quite) possible.

To demonstrate the problem I'm using the Logs -> Planks auto-crafting system from Botania 221-224 Visual Changelog. The only changes I've made are adding a Corporea Index and adding a few repeaters between the and-gate and the Retainer to delay the signal long enough to allow the hopper to fully empty.

The problems:

1. Request 4 planks with 3 planks in the corporea system. You will be given 7 planks. That's because when the Retainer gets a redstone signal it repeats the original request for 4 planks, not taking into account that 3 have already been delivered.
2. Request 64 planks with 0 planks in the corporea system. You will be given 4 planks with 4 more being auto-crafted but left in the corporea system. That's because when the Retainer gets a redstone signal it repeats the original request for 64 planks with only 4 freshly-crafted planks now in the system. That triggers the Interceptor for a second time but it doesn't cause the Retainer's comparator output to turn back on.

The behaviour in (2) is probably by design to avoid infinite loops but if (1) is fixed then such loops should not be a problem.