I am sorry, I can not answer your question but I leave you a message because I saw that you pocess a VFA almost the same as me.
I posted on "water" topic as "Water line supply >> water tank supply"
Perhaps can you give me an answer about this post as you have a VFA and as on the picture your VFA seems not to be on water line supply.
my question : "Does any VFA Expres machine owners or other espresso professional machine owners try to transit from water line supply to water tank supply?"
Thank you by advance