That's the screw mark of the shower screen in the middle of the puck - do you need a bigger basket/dose down?
Yes it is but no I don't. I'm from the old school of thought where you don't leave a head of water at the top of the puck. Channelling is reduced by not leaving anywhere for the coffee to go.
No qualms - but might be exacerbating any 'squirt' as in your last, which would of course in turn allow channels to form. If old dispersal plate was working I guess next step is to machine the new one as planned!
Yes it is but no I don't. I'm from the old school of thought where you don't leave a head of water at the top of the puck. Channelling is reduced by not leaving anywhere for the coffee to go.