I agree with Andrew as well. When I first was getting into wet plate, I thought two things. I thought traditional Sandarac was going to be too tough to work with and I would NEVER use KCN as a fix.
The first thing I did when actually started shooting on my own was make a great batch of Sandarac and started fixing with KCN. I think Sandarac is easy, gives a great result, is archival, has a great gloss, etc.
I only use sodium thiosulfate when doing collodion negatives, otherwise I prefer KCN. But it MUST be respected when handling and storing etc. if you do that it is fine, it fixes and rinses fast. Know about safe handling before using.