Back in 2019 I experimented with shower screen spaces which eventuated to my current group design which has been in use since 2021. The current spacer replaces the lower brass distribution block and shower screen with a custom part machined out of PEEK and IMS CI-200 screen.
I designed it around 18g dose of medium beans in a VST 18g basket for optimal head space. The .step file is available on Basecamp Diaspora, however it is only suitable for v1.0 machines.
It cost about $400AUD to have machines, not cheap, but I’m very pleased with how it preforms.