The B&M plug kinda sucks. Too thick, you leave whatever oil is lower than the thickness of the inside nut. The nylon washer cannot be tightened as much as needed either. You want really tight there because you have to loosen the plug while holding the outer nut or the outer nut spins free and then loose, the only resolution then is to pull pan again. You can even slightly loosen it using the double wrench method since the nylon gives with time. The plug is also low enough it can snag things to wreak havoc with pan depending on where you locate it.
I make up my own by shortening inside nut height and aluminum washer for no give and super tight and an allen plug used after tapping the 1/8" NPT slightly deeper. Then no plug sticking out, entire assembly tight as sh-t and the oil pretty much all drains out. Fixture located about in middle to take advantage of the stock installed trans angle, the trans will rub back surface before fixture contact, it also clears inside filter and any thing else. Two cars fitted up and not a drop leaked.