Pondering and researching and applying common sense, I decided not to do the $300-plus testing.
Allergies and sensitivities are fickle things, even if I test ok on something that does not mean I will not react, so there is nothing served by having substances stated as "safe". Another way of testing seems more reliable and not costly, to put a sample in the mouth between cheek and gum, do that repeatedly for a couple of weeks and see what happens.
The other tests the naturopath-chiropractor does do not seem to be any help to me. I already know I have mercury in me because of the drug recall for high levels, I used it heavily for years, and my symptoms all correlate with mercury toxicity. Plus the fact of having many, and some very old corroded, amalgams. So it's pointless to do a test to say, yes there is mercury, and yes, it is disturbing the organs, I already know that.
The last test, "buccal currents" to determine order of work - I already know where to start by the pain in a tooth. Then most corroded. After that I'm not concerned, they all will come out in a not too long period. So I can't justify spending $300 on unnecessary info. I am curious why he says detox should not be done while amalgams present, but will search elsewhere for the arguments.