Could I use TF4 to fix argyrotypes?

If I diluted TF4 down, could I use it instead of sodium thiosulfate to fix argyrotypes?

I'm thinking down to a 2% solution or thereabouts...

In his monograph on the Argyrotype process, Mike Ware states that prolonged washing in the fix can lead to loss of density in the highlights, so a rapid fixer may be too aggressive for the fine silver particles in the image.

Also, if the TF-4 is on the alkaline side of neutral pH, there is the possibility of residual iron being left in the print. A problem that the Argyrotype process had been designed to prevent, as residual iron(III) can oxidise the silver causing image degradation.

That is not to say you shouldn't try it, just keep the potential problems in mind.

You can use it dilute, but you may wel cleared the print before. I suggest you to first give a wash in non chlorinated water (I use tap water I keep in my lab for a day before I use it) hten get in citric acid bath to take all the ferric out and tone ingold, palladium or platinum and at last fix.