When you estimate a home's value, whether you come up with a specific number or determine that it is worth less than a specific amount, you have appraised that property.
Accepting a trip fee because the value estimate, in whatever terms it is couched, is too low for the loan to fly is a violation of USPAP. You have just agreed to let your fee be determined by the value. It is unethical, wrong and bad business practice to engage in this kind of idiocy excused by sophistry of the simplest sort.
Appraisers who do this encourage lenders to exert pressure on all appraisers. You may be helping yourself with a particular client, insuring that you get the lion's share of business in your coverage area, but you are performing a disservice to the profession and to every other appraiser in your market and elsewhere, too.
I am a professional and peform a professional service for my clients. I am not a loan facilitator, I am an appraiser. It is not my job to cover for ignorant, greedy loan originators who are too damned lazy to make the necessary effort to determine whether an appraisal is justified. I am not going to lose my license or get reprimanded for breaking rules we all are supposed to know and follow.
We all need to inform our clients that if they are unsure of whether a property's appraised value will be sufficient for a loan, then they should either find a realtor to do a BPO, or drop the deal. I tell my clients that if I go, I get a full fee, regardless of the value. If that doesn't work for them, they can call someone else. And, guess what, there are always guys (and gals) out there who are willing to do whatever it takes to get that lender's business.