So I had previously signed up for the beta for PS4 on the off-chance that I'd actually get selected (I never do), and when I tried to redeem the code that I got for a PC copy, it said:
'You are already registered on PS4 with the following email. We will contact you via email if you are selected for our future beta phases.'
So I can't even have assuredly get into the beta DESPITE having a guaranteed access code.
Create another ubi account for the PC code.