Nothing's changed about report development with the advent of UAD: if you had enough information to do an appraisal with only an exterior inspection reported on the 2055 in August, you ought to have enough information today.
That said: the scope of work of the 2055 requires you to "obtain adequate information about the physical characteristics (including, but not limited to CONDITION, room count, gross living area, etc.) of the subject property from the exterior-only inspection and reliable public or private sources to perform this appraisal." Then, certification 10 requires you to verify from a disinterested source all information provided by persons having a financial interest in the financing of sale of the property.
Information about living area, construction, exterior features, etc. can probably be reliably be verifed from public records. Around here, room count is not uniformly reported. Assuming the property has recently appeared in MLS, that might be considered "reliable" but there's obviously an argument there. Your concern about reporting condition is a valid one.
Also, since you can't limit the scope of work, you don't have any wiggle room if anything about the property is other than what you say it is. I regularly and frequently turn down these assignments if I don't think the available information is adequate to comply with the scope of work. I do have the impression that there are enough appraisers accepting these requests that there is no reason for lenders to stop ordering them.
