it's what relation does that mod have to with the replacement of a small box in the panel with another almost identical small box?
Problem is, how to set up a prescriptive system with sufficient information to allow folk to determine in advance of a determination that the situation is as simple and unrelated as you infer ?
I agree, wholeheartedly, that a significant proportion of (GA) mods (in particular) are trivial and easy peasy for the incompatibility assessment. One still needs to cover the complex animals and a way of not trivialising the categorisation of each.
I can't give you the answer but, having been there on both sides of the table, I can detail the problem. (One of the few times, I guess, that an engineer has a problem but not the solution .. usually engineers are characterised by having a solution looking for a problem).
the fee should reflect the work involved
but that needs to be done on a rational basis with all costs, including the hidden on-costs, included. Unless the job is on a mates' rates foreigner deal (and, even then, the delegate or AP carries the liability cost), it is going to cost some real dollars .. only the quantum is to be determined.
is killing GA
tell me about it .. I get fiscally raped regularly by the design folk I use. Sometimes they are worth their weight in gold .. for simple jobs the overheads get up my nose. Gets a lot worse the further up the formality chain you go, I'm afraid.
but from my point of view
appreciate your frustration but do consider it from the LAME's, owner's and pilot's position of liability. While I can't speak to the two last, the LAME who does a down and dirty assessment can find him/herself way, way out on a limb and penniless after the mishap and subsequent sequence of legal fun and games.