Not sure I’d recommend the wood glue technique on anything porous. Works well on tile, plastics, and acrylic, but I don’t know how you’d get it off of rough stone or wood.
As for traditional masking and Baltic I think you’re never going to get a great result with any paint that the fibers will absorb. Sealing the wood first is the way to go.
That said if you really want to keep trying traditional masking and can’t get the masking to hold well enough you might like this post about getting a better masking seal on woods like BB ply.