AnFI, and any others still confused about this:
***before you listen to me, reread post #83, brilliant description***
***I don't fly 135's, but the design features are not unique***
What SS is trying to point out is that the goal of designing small feeder tanks, and it is a common design feature in one iteration or another, is to prevent the scenario you are describing.
Yes, the main tank transfer pumps will move in and out of fuel but they do not supply the engine. They are there to keep the supply tanks full.
The smaller feeder tanks and feeder pumps supply the engine, with significantly less space for sloshing fuel.
Yes, there is a possibility of a pilot moving from hover to forward speed and leaving the transfer pumps in an inappropriate configuration, but it is a known issue. And as was posted, the checklist response will address this.
Finally, if the pilot has turned off a main tank pump because of a light (indicating run dry) then it will not be intermittently sucking fuel later.
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I am not trying to start a pi$$ing match, just to point out that the system is not unique, particularly complex, or obviously flawed. Design is compromise. We get paid the big bucks to figure it out.