Feels terrible to say this, but welcome back. If only one of us was wealthy enough to hire a team of professionals ranging from derms ro GI to allergy specialist etc. etc. to congruently come up with a solution. Unfortunately we are all poor and unable to really get more than few minutes with the doctors, most of whom just repeat the same treatments as the previous ones always with this line "Let's try it my way".
EC is definitely a wound (abrasion type) that never heals. If a wound is irritated (like when we talk / smile / etc.) it becomes more sensitive and our body grows more dread skin around it to protect it. Unfortunately, this wound never heals so the crusts never go away.
I feel like hypothetically if lips were left alone for quite a long time, it would heal just like other skin wounds, however it is impossible in our condition because not moving lips means no eating or drinking or anything of that sort.
I feel like I have not provided any constructive ideas and just reiterated previous posts, sorry about that.