Hi joshS,
You could use a US Mid-Grade blade but you would have to trim the diffusion film so the blade can sit deeper in the socket of the emitter without the film wrinkling.
HOWEVER because the US blade has a thinner outer wall (making it lighter) it might not fit as tightly as the Saberforge blade designed for the Thin-neck. This could mean your blade could be pulled loose with a strong contact as it would flex more.
Hope this helps
For Tyeth