u/Big-Challenge-8949

So I was looking at the uspsa production rules today and noticed this. With the external plugs, would that apply to the C&H speed feed pro or similar "butt plugs" for the glock frames? I keep getting people telling me I should put one in, but always thought it was illegal. But based off of 22.3, as long as it doesnt extend below the heel it should be good?? or would that count as an internal plug and thus change the internal magwell dimensions.