You're welcome to believe whatever. Fact is, for a shapeshifter runner in 2075, you're talking about experimental prototype genecrafting techniques from the 50s or 60s (at least) - imperfect techniques on a poorly understood subject to create untested augmentations. That's enough for me to say that it's not perfect fluff side.
Then on the mechanics side you have shift's delta requirement versus the standard or alpha prototype reality.