does anyone do a two bath fix on film? I could certainly see it for open tanks (dip and dunk) or for tray processing.

In fact, I'm wondering if moving to Thomas' method (which seems to be Ilford's recommendation for print developing) for all of my rapid fixer need would be the most reasonable option. As it is, I seem to err on the side of under-using fixer rather than approach exhaustion limits.

By the way, there are fixer test kits on the market, and if exhaustion is a concern you can certainly check your fixer strength before using it. You also want to filter (with filter paper) the fixer before putting it back into the bottle and before using it. Nobody is happy with silver deposits on film.