MIDI Solutions Quadra Thru V2 4-Output Active MIDI Thru Box at Juno Records.
Keytech MT series MIDI Thru box - Gearspace.com
New Audiaire VST - plugin that sends MIDI CC and Sysex on custom controllers so you can sequence ever parameter on any hardware or software synth : r/synthesizers
Selector by Vague Software - MIDI Plugin VST
Music Box Suite – FrozenPlain
MeeBlip Thru5 Introduced, New DIY MIDI Splitter Box With 1 In & 5 Outs
MIDI Solutions Quadra Thru 1 In 4 Out MIDI Interface