The right kind of physical therapy for ALS is absolutely necessary - and it would be beneficial to have an ALS certification for physical therapists. When my mom was working with physical therapists, one of the "supervisors" came to do an assessment, and wanted her to stand on her own, and kept pushing her to keep standing, even though she clearly was ready to be done. She kept standing, because the physical therapist said to do it. That was the last time she ever stood on her own.
Physical therapy for pALS is to keep their movement as long as possible; they are brand new to the diagnosis, and should not have to rely on their limited understanding or research to be able to advocate for themselves. An ALS certification for physical therapists should help with this, to help reinforce for the physical therapists what not to do, and what can be done to really help the pALS and cALS.