The advice here is wonderful. I'm going to review my own process and tighten up my discipline a bit; mostly to save water, because although I get great results, I'm perhaps overly generous with the wash. We really need to be concerned about this. Photography uses a disgusting amount of water. A commercial color lab with several roller transport processors could be like a small river - and incidentally, produce solid waste that could shame a small city. The migration to digital color has probably improved this, but of course, introduces other environmental problems.
I have used the combination that you ask about quite successfully. Ilford warmtone untoned looks a bit greenish and not very lively to me; I don't like the tone very much. Just the right amount of toning cuts that tint, improves the depth, and produces a coldish brown much more to my liking. I use the toner both for the way the print appears, and to enhance permanence. It is my main printing paper these days, but never without toning.
I dilute my toner about ten to 1 with H2O and watch it carefully, never toning more than a very few prints at a time, usually only one. I keep an untoned sample to compare the tone with, and after the first, use the previous print as a target. The tray where I place the toned prints is being continuously refreshed by running water. Remember that toning continues for a time until the toner is gone from the emulsion. The toner lasts a long time.
The idea of evaporation of the toner is great. As for disposal of the fixer, I try to use a local recovery. If you can find a medical/dental x-ray facility that recovers their fixer, they may be willing to take it. After all, the price of silver these days makes recovery worth it. Sometimes the hazardous waste guys balk at taking photo stuff if they suspect that you could be a business. Having been one, I suppose I'm more wary of that. If you don't take a lot at a time, no problem.