Can you hide plywood seams on round off?

I didn't think about how annoying plywood seams were and now I'm jumping through hoops to smooth them out after gorilla putty.

I know about the Orion on veneer but I wanted a round off on my corners and top platform. I'm using marine plywood 3/4" fir. It's absorbing unevenly so I puttied it and it feels impossible to get it flat and smooth even with 240 paper and that's not even considering the round off I made.