thanks for the kind comments Gumphri. The system originated in UK, on green oak frames. Given their climate and the movement of green oak, I'm considering this the worst case scenario..lol
My seasoned white pine, old growth doug fir and mild Ontario climate are no match to what the guys in UK have to put up with.
The EPDM gaskets are spec'ed specifically to address the movement of frames. With a 1/4"-1/2" channel around the glass/packing pieces, the glass is allowed to float on the frame.

there's a thin line between hobby and mental illness