I'm finding myself wanting more speed than I am getting out of HP5+ with Pyrocat HD (slow) or Rodinal (nearly box speed at lower dilutions). Microphen is probably the most obvious choice and is a compensating developer which I like.
But Microphen is expensive, and for actual speed increase you need full strengh. Ilford's product info indicates it may be reused in deep tanks or spiral tanks. I tray develop by inspection. I wouldn't be able to fit a tank line into my camper's tiny bathroom where I'll be souping film for much of my current project.
Why does Ilford not recommend reusing Microphen in tray processing?
Does anyone do it anyway?