Did photographers years ago fix and wash this paper? Or, did they just Gold Tone it and wash? Or what general method was used to ensure a fairly stable final print?

I remember playing around with Kodak POP, and fixing resulted in considerable lightening of the image.

I understand more recent (last 50 years) use of the paper as a proofing medium..the impermanence of the image was desired..so the studio could sell conventional b/w prints.

Sometimes it was just washed, providing a proof print that would fade in a few weeks (seems like a good idea to me).

Sometimes it was fixed and gold toned, or gold toned and fixed, or even treated with a gold-toning fixer.

Fixing done properly doesn't bleach the image (much), it only changes the tones to a lighter brown. Gold toning darkens the tones again so the full range is more visible.

So what is the process one would follow to ensure stable/archival prints from POP that would not fade? Would it be expose, wash, gold-tone, rinse, fix and then a final wash?