Worried about enough flow, great, let's add further resistance to the mix. I think I'd be looking to decrease resistance to flow, not add things that increase it. Increasing resistance would seem to increase stress that the pump must overcome, possibly decreasing it's useful life cycle. Unless I'm missing something here, regardless of how minimal the additional resistance is, it's seems like an unnecessary addition.
Many folks remain averse to bay reservoir due to past leakage experiences (perhaps a thing of the past now, perhaps not) as well as vibration. Seems if you were gonna put it there, you would have it measure flow, especially for $80+. Flow resistance is no concern on a D5 or DDC pump, it's minimal ... it's not as if it were being used on a CLC pump which can't afford any resistance whatsoever.
This thing will make you bold from frustration. I have Zalman Resarator XT which had same flow indicator as soon as there is some tiny bit of gum the propeller stopped and so did the cooling since it's thinking it's leaking or there is not enough flow, even though you couldn't see nothing. Ultimately I had to dis assmble it and grind off 2mm of the fins so it can spin freely. And from what I see it's the same design and it will be a lot harder to dis assemble this since it's inside your case.
If you have "gum" clogging up your paddlewheel, I'd be worried aboutwhat is stuck between your block's microchannels. The openings here are far smaller than the fin clearance.