Being that this thread was titled "fire basket to upgrade WEBER KETTLE" I was speaking specifically for kettle use only and not for your version of the PBC.
If I were to remove the three blades as you suggested there would be 3 air inlets which I would no longer have control over:
If I cannot control air flow I cannot control temps manually. If theres no desire on your part to make this work with the Kettle I would suggest deleting this thread to avoid confusion. I thought your design had functional merit but there was a design flaw with the blades being in the way.
Also, you give the option to a Kettle user of having basically half the cooking space(1x 22inch grill) of a UDS for $60, this is in a very good price point to be competitive for what you are offering. There is very little installation for the user if you can find a way for the basket to sit tightly/firmly against the blades. Finally, the user still has a fully functioning grill with the removal of fire basket. To me, that takes this design from good to great.