Using same bottle of fixer for Tmax and TriX400

I am considering re-using fixer for film processing. The brand of choice is Kodak and it's Kodak professional fixer. I know Kodak specifies maximum lifespan for Tmax and all other films per liter. Is there any problem, other than needs to keeping an accurate tab of numbers, to fix Tmax and other films (TriX400) with the same batch? In other words, fix Tmax, put the fixer back in the bottle, and use the same bottle to fix TriX400?

I know Tmax has dyes in the film that comes off when processing. Would this affect TriX?

No problem at all, though I really don't like the Kodak powdered fixer all that much. It works and there is no problem using it for any combination of B&W films up to its capacity. I just don't like it because it contains a hardener, works too slowly, and has a relatively low capacity. The hardener lessens the efficiency of the final wash, and the low capacity can actually make it more expensive to use than a good liquid concentrate rapid fixer.

Whatever you do, DO NOT use the same bottle of fixer for film and for paper. You can use the same type of fixer, just use separate batches for each. Fixer that has been used for paper picks up a lot of detritus - lint, dust, etc., that may find its way stuck onto your film. Once dried, it is damned near impossible to remove without damaging the emulsion.

I knew about not mixing film and paper. (different thread)

I'll keep a one-liter bottle for film only then. Thank you for your response.