Finishing Breadboard ends

I’m building a jewelry box that has breadboard ends for the lid that I’m likely going to finish with Arm-R-Seal. If I apply the finish with the ends assembled to the lid, will that bond the ends and lid together and negate the allowance for movement that the breadboards provide? Will the finish just crack? Should I finish the lid and breadboards separately, then assemble and glue them after the finish cures?

-- measure twice, cut once, swear and start over.