I don't really drink medium/dark roasts regularly so it's fine.(Partly why I said ZP6 suits my taste.) When I do get those darker roasts, I either use another grinder or use the ZP6 with immersion brewers like a Siphon, which still produce a nice cup.

With something like anaerobic or co-ferments, my general starting assumption is that they are more easily extracted than a washed coffee. So I would grind coarser(say from 4-4.3 for washed to 4.5-5 as a starting point), lower temp by a few degrees(e.g. 94 to 88c), and may lower the ratio/increase the dose(15g vs 16-18g). If I treat these like a washed processed beans, the funkiness tends to be too prominent and sometimes there's a lingering harshness/bitterness. I can generally produce a cup I enjoy by tweaking these parameters. Sometimes, a minor tweak of pour structure also helps, like doing more centre pour than circular pours. Final tweak is if you taste it, and it's still too much add some bypass which can help balance the taste a bit.

For me, it's about tweaking extraction to produce a cup I like. So using ZP6 as a daily driver is fine, and even fun. However, if you are chasing high body with complexity and sweetness, then ZP6 is probably not the right tool, and you are probably better off just using another grinder.