Is REM necessary with hearing test conducted with hearing aids?

[Adrian]

Here:

Real ear measurement vs. in-situ audiometry

I had a discussion with my acoustician. I wanted to have a real ear measurement and she said that the Signia 7x can do an Insitogram via software. Are the 2 techniques compareable? Theoretically, the structure of the ear is also taken into account with the Insitogram via the hearing aids.