I have an old Osram Duka 50 sodium safelight I used to use all the time with RA4 and even Ilfochrome and Kodak Type R paper (which always insisted on no safelight) and never had a problem or detectable fog. I used the lowest setting and bounced it off my white ceiling, but it was bright enough to make out the outlines of everything in the darkroom and that was a big help. I still have it but once it burns out I'll have to get something else. I have a Jobo Maxilux LED that was supposed to be safe for color but haven't tried it, and it doesn't seem it will be nearly as bright as the (already dim, used that way) Duka 50.
But with an appropriate safelight it's definitely possible - or was, and I'm pleased to learn that today's very fast papers aren't any less safe with a proper safelight.