@Greg H.
Totally agreed that the location counts when discussing obligations for 'disclosure'. I have worked in TX, KS, and MO and totally agree that laws, guidelines, documentation, and typical practice varies quite a bit.
Your note about FHA appraisal on file for 120 days is an important note as well. The info source I went to states that, "A VA appraisal stays on file with the VA (and therefore "sticks to the house") for a period of 6 months. This would only affect VA loans on your home. FHA also stays with the house for 6 months and only affects FHA buyers."
Those timelines could work for or against a seller based on their objectives. Sometimes, a buyer saving the cost of an appraisal might be what makes the deal work. But, in cases of low appraisal I have seen it work against the seller. I originated VA loans previously and did see some appraisals that sellers considered to be very low - locking them up for a period of time w/potential VA buyers.
My thought was more about the increasing availability of public data and sales data that is accessible online. Some of those resources reference appraisal and mortgage data so if an investor has one done the data may be visible. (not necessarily in a seller disclosure document).
All good food for thought. In any case I would, personally, not obtain a formal appraisal as my method for evaluating the deal.