Has anyone every heard of an appraiser getting in trouble, either in Court or with the state board, because of a 2055 with incorrect GLA? Yes, anything is possible, and I would be interested in hearing comments from anyone that has seen this happen, but this seems far fetched to me.
In theory, you should have a good understanding with your client about the intended use and scope of work. I know that in practice, it is not always possible to have a detailed discussion with the client about what will and won't get done (scope of work). It seems reasonable to me that if the client asks for 2055 exterior inspection (drive by), they have no right to expect you to measure. If the client asks for 2055 with interior inspection, it is not quite as clear cut, and this thread shows that opinions vary, even among "experts". If an appraiser did a 2055 with interior, did not measure, and disclosed that they did not measure in the report, it is hard for me to imagine a scenario where this would come back to haunt the appraiser. Impossible? No, not impossible.
I see the 2055 as an effort to provide the client with an option to spend less money when a limited scope of work is acceptable. For example, the borrower currently owes $100K on a house that they bought 8 years ago, they have been making the payments right on time every month. The out of town lender just wants to verify that the house did not burn down recently. It is a very low risk loan, the client wants to improve turn time and keep the expense down. In this example, the appraisal industry shoots itself in the foot by saying, either full fee (and normal turn time) or find someone else.
No appraisal is ever 100% reliable. No matter how much work you do, there is always something more that you could have done to make that appraisal "better". Where you draw the line and say "enough", and move on to the next report is always a judgment call. I am not advocating shoddy or misleading work.