box it up it will be ok. that is not a lot of cutting. I assume you have welded in sub frames connectors
what hits there that needs clearance?
Guys notch 1st gen subframes to clear LS AC compressors all the time
Here you can see a notch near the RF UCA, boxed in and welded. Guys who routinely beat the snot out of their high hp cars in more than one direction.
