Rod bolts fell out!

Re-sizing the rods will not fix a loose bolt hole....??? I'd check the holes for size for sure; if they are enlarged, try to figure out why.

BTW as for SCAT rods.... they will not cost much more than the re-sizing of the stock rods. As for balance, they will weigh something like 150 grams under the stock rods as for total weight. The change in bobweight on the crank will be on the order of -250 grams + or -. That will mean 1-2 holes drilled in the end counterweights. Not a big effort.

If the pistons weights have been equalized (as it sounds); that is easy to confirm with a scale on your own. If that is true, and since SCAT rod will all be closely weight-equalized from the factory, that means you can do this with just touching the crank for a new bobweight computed value.. and touching nothing else for balance. I can go into the details more if that is of interest.