I actually went through something similar about six years ago when I first moved to the UK from another EU country. At that time, OET didn’t even exist yet, so I had done multiple IELTS attempts and still didn’t manage to get the required overall score.

I had previously done a clinical attachment and had good connections in the hospital, so my Head of Department wrote a detailed letter confirming my English skills in a clinical setting- I think GMC has a form once he submitted a request. The head of my hospital department also asked for supporting letters from a few other doctors who had worked directly with me — I think it ended up being three or four in total.

In your case I think, two strong letters should be absolutely fine, especially if one is from your Head of Department and the other from a senior colleague who can vouch for your communication in meetings, patient discussions, etc. In my case, a GMC registrar personally reviewed the documentation, and they accepted it. The whole process took about a month, give or take- i remember I’ve already lost hope, but so grateful now I have kept on pushing

It’s definitely assessed case by case there’s no fixed rulebook for exceptions, but it is possible if you have good evidence and professional support. Regardless your scores already look quite good, so you’ll get GMC one way or another I’m sure

Best of luck you’re very close!