I don't know about the Dag boards since I don't venture there, but in Bel, the discussion has come up that if it were done properly according to the historical methods (15-30 layers of linen, not a couple cotton t-shirts) and didn't look like absolute crap, then it would most likely be passed by heralds' discretion even though it is technically not legal armor.
I wish you the best of luck if you attempt this endeavor.