It works correctly when I'm in the Administrator role or in the technician role that it's the default SO form for

The other roles must be using another form? Try looking at the preferred forms used by the other roles, and you can then update those forms to us the Advanced PDF Layout.

There are two different sales order forms in use. I want the sales role to keep using the main one as its default, but when they print an SO that uses the technician form, I want it to print using the one defined in the custom form saved with the SO record. I do not want to change the default form for the sales role. Is there a way to change this at the form level instead of at the role level?