Update: Tested my Tetenal Vario in "normal" developer - and it's badly fogged. This may have something to do with why it work where it shouldn't (in lith)? Anyway, the boxes I have will be lith-printed only.
Varycon goes peppery all the time, great fun if that's what you want. If it's coloured highlights, that's a bit more difficult. I'll try adding a lot of sulfite and bromide at the end of next session, just to see if it works.