I guess I'm looking for empathy more than anything else here. Does anyone else find it near impossible to pull a lungo (without under-extracted bilge water decorating their face)?

Whilst I rarely have problems with dosing/distribution for a standard espresso or ristretto, there seems to be a point of coarseness above which I can't avoid terrible channeling. This isn't a problem normally as I can just tighten up the grind a little, but someone asked for a lungo today and I just couldn't deliver it.

Is a normal experience?

Coarse grinds take up more room and swell more. If you mash up to the shower screen before the fines have migrated, you're going to have a lot of problems. This means you'll end up with less coffee, by weight, when you pull lungos or cafe cremas in your usual basket. So the easiest way to get them right is to use a triple basket and leave plenty of headroom.

That makes a lot of sense, thanks so much. I'll try it out next time my granny needs her caffeine injection.