I take the Pacific surf liner fairly regularly. Agree with everything here. They generally an ounce all stops but, suggestion, set a timer on your phone or something for 10 minutes before your arrival time just in case. They will usually let you board with the business class passengers.

It will depend on what line you take, but most trains that I'm aware of have audible announcements at each stop. When I go along the Eastern Corridor, the conductors usually let me know when my stop is coming up. The train stations often let disabled people on at the same time as their Business Class passengers. If you made a notification about your visual impairment when you ordered your ticket, they're usually trained on how to accommodate various disabilities.

Like most travel services, I take a "trust but verify" approach when it comes to provided accommodations since there's always a chance someone isn't trained well enough or another passenger is distracting the staff. If you can advocate for yourself and your mobility is otherwise independent, then your chances are pretty good.