I’m on 2 different SIs and deal with the former head of CAMI’s Airman Certification as my AME and I’ve not found your concerns about AMEs or the people at CAMI to be mainly concerned with CYA.
Good luck with the process. Your best chance of success will be to do exactly what they ask if you, take the tests they request, and give them the test results they want - and if you meet the criteria which is well defined you will be granted your SI.