While I can not comment specifically to the post Covid Long Haul symptoms, I can comment about the lingering dryness, dry nasal passages.

While 11 weeks seems like an eternity when you are unwell. To the body it is just a small blip of time in the process of healing. Your body is recovering from a more intense virus than usual, so it naturally will take a little longer to return to homeostasis.

I can tell you that seeing an ENT will do nothing for you. They have nothing different to offer suggest when it comes to virus/cold recovery than a PCP. While tempting to want to see them for dryness/congestion type feelings there is truly nothing they can do. They are surgeons FIRST and foremost. Outside of what your PCP can offer, they can only visual see things with a longer scope. They will do it due to the appt you’ve made. They can tell you what they observe of your mucous membranes. Outside of that they want to be performing surgery on people.

Allow yourself the total overall body approach you need to heal from a virus. Overly hydrate, high nutrient dense fruits/vegetables and vitamin supplementation for healthy immune system. Focus on immune support overall.
Try not to focus just on appointments for one specific area. And be cautious when getting advice to use nasal sprays and rinses for dryness.
At the risk of sounding harsh, if you are on your 3rd ENT, you are truly waisting your energy.