Rudeofus - this is interesting. So - is there something to be done to quench or otherwise sequester those pesky free-halide ions? Or is it as simple as ensuring there is sufficient 'excess' developer to mitigate this?
Not really, and this will eventually kill every fixer even if you somehow remove/recover the Silver. Note, that not only the solvent liberates halide ions: where do you think they go when you develop silver?
Trying to be the best of whatever I am, even if what I am is no good.