Feedback loops through machines

There was a question on steam BP forum recently about “Feedback Loops” through a machine to process an ingredient multiple times.

I’m hard pressed to find a scenario where multi-processing of an ingredient makes sense compared to just buying multiple machines, but maybe in space-constrained scenarios it would be used.
However here is one line that WILL process an ingredient TWICE before sending it to a pillmaker.

Its hard to see the color difference in ingredient so I tried to label the 5 processing steps (2 and 3 look very close but are different).
each ingredient will go through the “loop” noted by blue arrows once, being processed by the dissolver a 2nd time before exiting to the pillmaker.

The steam question referred to Crossroads, though IMO, t-belts are the closest to "decision/"logic? splits we have - though it is really a matter of timing and not “logic”.

The shaker is b/c I believe I need a machine to force the T-Belts into a loop, and b/c I just wanted to test something that didn’t change concentration or ingredients (and in this case needed a 2X process time machine).

Has anyone improved on this? or used a 3x or 4x processing time for mroe than 2 times through a machine before “exiting”?

To really use this you’d probably want a machine that functioned as an If statement.

If concentration >= x
outport via Port 1

else output via port 2.

Like SpaceChem’s testers for example.

I can forsee scenarios where you’d want to do the same process twice for example, either to save buying two/three machines expensive (i.e. one pair of triplicate chromotograph’s rather than two) or save space as you noted. The downside is you’d only be able to do it with machines that had a process time of one in the main loop and the output would effectively be as though it had been through a process-time two machine.