MODULAR Static Mesh on Marketplace?

Hello!
I want to publish MODULAR Static mesh on Marketplace, I know that modular assets must have meshes that snap together cleanly on the standard 10cm grid.

But, I can’t even use 5cm grid, it won’t work like I want it to work, and it won’t be like I want it to be.

For example, I have cockpits, in interior section of them, I can’t use snap on 10cm grid, maximum I can use is 1cm.
Because it wouldn’t be like I want it to be, it would be a button here, then that switch wouldn’t match where it should be. I think you understand my point here, so my question:
What should I do?