Well, I'm no doctor or scientist, but I think the way that my EC "spread" to the 'healthy' upper lip may show that the two lips may be connected somehow, meaning that MAYBE if you try healing one lip at a time it just won't work because half of it is affected as well. This is just my opinion, and I'm just basing it on what I think and also I've never read a cure where they try to heal it one at a time. If there is, then I definitely haven't been reading enough. Also, if you do plan on doing it one a time and in time it actually does heal, then that means we have another relevant info regarding EC, no matter how individualistic all the treatments are.

Yes that's what I was thinking as well. In my point of view, EC is only a localized issue regarding the lips themselves and anything else is a different issue. Dry skin, psoriasis, eczema etc. occur in different parts of the body, EC may somehow be connected to them if this is in fact an immune problem like those mentioned above, but I really don't think it should still be classified as EC if it has spread around.

Oh maybe you've read my post then about my EC "spreading". While it is true that I may in fact not remember all the details regarding my lips because I barely cared about them before, heck I don't even know or remember if I really wasn't peeling anything after using the chapstick that I mentioned before, but I have pictures of my lips all throughout the years and the only damage I could really see was the bottom lip. Sure, the upper also gets dry in accordance with the lower, but even if I was somehow damaging the upper, I can attest that it is at least 99% less damaged and healthier than the lower.

Now I will reiterate that I am no doctor or scientist, and none of us here are. That's why we are all careful with our words and using only phrases such as "most likely" or "maybe", we may be close to 99% sure of what is going on but definitely not 100%. All the things I said regarding EC are also just my own theory as well and have no scientific basis. The only scientific fact we know regarding this is that... something is going on with our lips! Lol.

I think leaving alone one lip at a time would work and would heal, but it would take forever to have both lips healed. The healing time is already ridiculous, so I think getting it just over with makes more sense. I'm 6 1/2 months into leaving them alone and my lips aren't 100% perfect yet, and I can't imagine having to sacrifice all this time again. But yeah to answer your question i don't see why it wouldn't work. Also the leaving one lip alone healing is assuming trauma is the only cause. If you also have an internal cause (like gut issues people talk about on here, etc.) you will also have to do this with leaving the lip alone.
And i don't think it's spreading when leaving the lips alone. The skin just keeps building up on the lips and so much forms that it covers other parts of the lips.
For the EC starting on one lip then the other, one lip contaminating the other doesn't make sense to me. If trauma is your cause, you might be biting one of your lips more frequently which is why it shows up on that lip sooner than the other. If it's an internal cause, well it has to start somewhere so going from one lip to both lips might happen.