dear Jeromy
i'm sending you a message of perseverance
1 gluing layers : beware of bubbles of air and density of the glue
that might be the cause of spitting ; also the timing between "gluing" and putting the layers in contact under press: depending on the type of glue , it can go from a few seconds (sometimes using an accelerator) to a good 20 mn
2 osage orange moisture : the use of a micro wave to speed up a drying is rarely a good option : time has no speed = better wait a few weeks to see if the moisture progresses, sanding is very often enough , or taking advantage of the change of tint in some parts , to enhance them...
now with birch plywood , you should end the project with ease
keep your hand on the plough !! hold on !
jim