ESA to UC managed migration - health conditions

I am due to undertake managed migration from ESA to UC and have a couple of questions:

(1) I note from the B+W guide that, during the UC claim, I'll be asked to give details of my health conditions. I have seen it said elsewhere on this forum that, if one is in the support group for ESA (as I am, and have been for some years), one should not record the health conditions here, but instead just state that one is in the ESA support group and leave it at that.

I don't understand why one would leave this information out, as surely it would be to miss an opportunity to give details to demonstrate continuing entitlement to the same level of support. I'm a bit confused and concerned about this dilemma: can anyone give guidance/explanation, or share relevant experiences?

(2a) Since originally being awarded ESA, my health has deteriorated and I am now diagnosed with additional conditions. Should I record these new conditions on the UC claim form (in case it helps me to demonstrate the deterioration - I'm wondering whether this would make a re-assessment less likely, and understandably I find the prospect of reassessment very stressful)? ...

(2b) ... However, if I do record these new conditions in my UC claim, would this be considered a change of circumstances - and if so, what would be the consequences of this?

Thanks in advance.