Is this the one that doesn’t have adjustable bed springs? I had a bed that wouldn’t level on the neptune pro with no adjustable springs and software couldn’t compensate outside of small prints.
I had to take the bed apart partially and use little shims (in my case tinfoil) to even the bed to the point where mesh leveling could handle the remaining flaws.
I put the foil in larger squares to fit under the silver metal tubes used as offsets for the heated bed. I’m not sure if foil under the pei will work, my worry would be making the bed uneven vs just adjusting the position. I just remember getting under the silver tube things was a massive pain in the ass so I do hope the pei sheet idea works tho lol