Straightening internal cuts

Good day everyone,

I recently cut out the hole in my table i am making but after setting it onto the internal frame, realized i had a lot of fluctuation on the cuts. I am looking for advice on the best way to straighten and make the cuts flush so its a straight drop

I was thinking i may need to cut more into the board and then add a trim piece to flush it as i need.

Ive included some pictures to show some of the issues as its hard to see from the larger picture

Where the plywood overhangs the frame, you could use a flush trim router bit:

I’m not sure if there is a great option where the frame is proud of your cutout. You might need another trim piece to cover the joint, or you could try a chamfer router bit to put a bevel which is straight to the board on the plywood piece.