Autism Gateway Assessment

Hi, I'm considering paying for a private Autism Gateway Assessment. I'm 36F and have been previously diagnosed with OCD, Anxiety and Depression. I'm considering the private path because I don't want to take up space on the NHS. 

The Autistic Gateway Assessment has been described to me as a 2 part assessment, where someone with MA qualifications conducts the initial assessment to determine likelihood of ASD, then a second assessment (paid for in addition) is conducted with a Doctor.

Has anyone here undergone anything similar? I would be grateful to hear about your experiences.