Hmmm. Might be just me and my snobbishness poking through, but I'm one of those guys here on HB who seem to be in the vast minority.... I like my beans fresh off the roaster. I try to use em up by the 7th day, but I frequently run into my self imposed limits on caffeine intake, so most times I've still got some of the week old batch and going into 2nd week with em... but, I never go more than 14 days, at that point I notice I start to get spritzers. Its a curious thing, as I have never before seen a spritzer in my life, when using commercially roasted coffee; something they must be doing in the storage processing? But when I started roasting my own beans, that's when I noticed I have to use em up before 14 days (I like very light roasts) or I am asking for spritzers in espresso. You may want to see if you can find a fresher bag maybe 3 days out of roast and see if that makes any difference.
....of course, before I started roasting my own beans I never had a bottomless pf, either
so could not have seen the spritzers if they were there. hmph, that might be it.
Just FYI, a lot of us wait at least 4 days post-roast (often more) because just-roasted coffee has high levels of carbon dioxide and other gasses. You may have a preference for freshly roasted flavors, but this is still worth a read: https://catandcloud.com/blogs/cat-cloud ... ete-licata
OP: I have the Londinium WDT and have never had a gusher, but I also have a lever machine (Londinium R). Are you being pretty aggressive about whisking the grinds? I do small circles around the basket pretty aggressively, make about 3 full passes, then do a little full circle motion to even out the grinds. I don't use a distribution tool.
Also, what tamper are you using? I started using Londinium's tamp and using my thumbs instead of my palm, and it's way easier IMO to see if the tamp is level (you can just naturally feel it).
Edit: Oh you're using LevTamp and distribution tool. Hmm. Other thought: do you have a zero-retention grinder? If not, you may be "chasing your tail", meaning you are getting old grinds first into the basket.