Most recently used a company called Triangle Plumbing.

https://triangleplumbingservice.business.site/

Actual service was by a guy named Doug, who was super friendly and helpful. He actually called 30 minutes before arriving, was 10 minutes early, spent 30-40 minutes and multiple tries to get the scope through, explained what he found (patiently), and called my buyer client, who wasn't present, and re-explained the findings when I asked. I'm not sure they are a large company, but based on my experience, I would recommend them.