I can tell you this. Truck drivers have used golf balls and engine coolant in this way and for the most part the real draw back is the temp issue and the long term issues as well as those tires will get between 100 and 300 thousand miles of use between changes. The physics of having anything inside the wheel explain how it works, and it does, some have even just used engine coolant and water. The issues in a truck also are that the tires are re-treaded 2-3 times and some end up with a million miles so damage to the inside can be an issue. It seldom is but I have seen pictures where it has been.
Long story short, It is very unlikely that something like a small marble inside a bike tire would have anything but a positive effect. Would I do it? With some experimentation, yes. I sure wouldn't pay for them though.
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