At this point on a quick technical level, it’s worth mentioning that the Lever group was never designed to be vented in the same way as other groups E61 etc… Venting it does introduce some issues, these were clear at the show in Trieste where the Vostok one group was demonstrated.
These are issues of design, a design that didn’t require venting and thus didn’t cater for it. The group stays pretty clean above the shower screen, although there is a little residue after the number of coffees we pulled on the machine at Trieste.
Paolo and I discussed some ways this can be mitigated to give drier pucks and less time the PF has to be left in the machine to drip drip drip. Especially important because the tech I helped Paolo come up with for releasing the lever automatically on pressure (or time) was meant to assist the production of accurately poured espresso on multi group machines in coffee shops. They don’t have the time to wait as at home, it needs to be faster.
When I tested the Nurri (ages ago), and the Vostok I found them materially slower to vent, then clean up the messy portafilter, than to let the lever work old style. Certainly not suitable for a shop. On my trip out on the 17th Jan I want to inspect the Vostok one group to ensure the changes meet with the requirements of Baristas in a shop, as well as at home….if it’s to be used in multigroup machines.
The software is actually designed for a multi group machine as well, each group would have a separate small control panel, so it could be set differently.