4 digits. A count that outgrows them keeps growing and is never cut.
Counter policy
Padding: 4 digits · gaps never reused · issued numbers are immutable
Next number, under PRJ-MHT
LNVAL-PRJ-MHT-0008
As far as this screen can tell: the number is given when a flow is issued, and it can be a later count. A change applies only to numbers issued from now on. The 7 flows already numbered under project workspaces keep their numbers.