This Pedal is currently available.
Buffered Volume Pedal
The Mission VM-PRO is the most sophisticated volume pedal ever made.
The VM-PRO resolves many of the common issues with volume pedals that cause tone sucking and mismatching problems. The VM-PRO works with electric, electro-acoustic, baritone or bass guitars. It also works with many other acoustic and electric instruments including electronic keyboards, steel guitars, and instrument microphones such as harmonica and horn mics.
VM-PRO includes on board buffers, isolated tuner out, sparkle control, and compatibility switches for use with active and passive pickups and fuzz pedals. The PZ version provides a 10M ohm impedance for use with passive Piezo pickups.
https://missionengineering.com/shop-2/products/volume-pedals/vm-pro/?v=7516fd43adaa