stop shooting test e - start shooting sust.
I agree. I'm all for the scientific approach, but there's a point where it just gets a little ridiculous. Just bang it back when you're done the test enth. The difference will be unnoticeable.
I'm obsessed with what I put in my body and noticed close to Jack Shit whenever I switched from enth to sust, and sust to enth. If you've been on for a while, you won't notice anything either. Just be happy that you have some nice new gear to start pinning. I love cracking open a new box of amps or flipping the top off a new vial. Grow time, bitches!