See the distance of the slot from the mouth of the InkMiser ? In an inverted bottle, THAT is the minimum ink depth required to reach the slot and fill the "funnel". Less than THAT, and you are back to pouring ink out of the bottle.
I'd bet against using the last drops ! I don't see that as the useful purpose of InkMiser.
Ever lower your pen into a bottle of Noodler's, not knowing how deep to go ? Are you submerging the nib, nib and feed, entire section, or half the pen barrel ? I doubt that InkMiser will access the last drops of ink. I believe that InkMieser will let you keep your pen at the top of the bottle, when filling. A worthy solution !
I really miss the Sheaffer Script ink bottles with the glass well at the bottle mouth.