Yes, you must do what is necessary to make it fit but that should not be a serious task. As has been said, there is an intention bow in the insert (the ends being higher than the middle. I would think you could see that bow if you simply laid the insert on a flat surface.
Without the inserts, run the bolts down into the table and back out. This should clear the threads as well as the hole.
You said something about cracking it. The intended bow is very slight. Securing it is not going to crack the insert.
Crack the insert, hmmm. Do you have plastic or metal inserts?
Not the best picture but I hope this shows how small the bow actually is. Two metal inserts face to face.
"Making Sawdust Safely"
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