You have well described a big problem in the field. Lots of people say they do EMDR but only do BLS. The approach you are using is the right one.

You might also direct people to this website so they know the things that can go wrong.

I say to clients, "what would you think of a surgeon who makes an incision where the patient demands without getting xrays and confirming a diagnosis?"

I also say, "EMDR is a power tool and so it can cause harm if not done properly. I want your EMDR experience to be successful and efficient."

It may also be that in your town someone is creating a particular expectation that EMDR is invariably fast. I'd check where the clients are getting their ideas.

Doing the right thing is often hard, but is never a mistake.