You might be right, but I doubt the EU are in a hurry to have another member with a land border with the UK.
The issue with the GB-NI border is that neither regime want to enforce it, but they both have to. Eng-Sco would have Scotland enforcing their (EU) side, and if Westminster didn't want to enforce their side - well, that's a win.
If the DUP were on-side with their treaty commitments the EU wouldn't give two shits about the GB border being unchecked.
The issue with the GB-NI border is that neither regime want to enforce it, but they both have to. Eng-Sco would have Scotland enforcing their (EU) side, and if Westminster didn't want to enforce their side - well, that's a win.
If the DUP were on-side with their treaty commitments the EU wouldn't give two shits about the GB border being unchecked.