Here the answer I got from Xavier :
"...
for the moment the TinyBox is aimed at the use with an FCB1010, the jackbox is intended as an add-on for 2 extra preset switches and 2 extra expression pedals. In theory it could work with just the jackbox, but I don't think it's feasible because you don't have any visual feedback (the visual feedback of the TinyBox is the FCB1010 status screen, which currently doesn't show the jackbox add-on). Also the Jackbox switches can't be used as "Bank up"/"Bank down" switches, so you would only have 2 presets available. In the future we might release a TinyBox which doesn't require an FCB1010, but which is bundled with the necessary electronics to create your own custom floorboard with up to 16 foot switches, (and an optional
jackbox to add 4 expression pedals).
..."
This morning he made a little complement to that :
"....
Actually you made me think further about the option of using TinyBox with JackBox, without FCB1010. Should be feasible, just a small
extension of the editor and firmware : in the current version the command "USE_JACKBOX" extends the bank layout from 10 to 12 presets per bank and extends the expression pedal assignment commands to support 4 pedals instead of 2.
I could introduce a command "USE_JACKBOX_STANDALONE" which turns the 2 switch inputs of the jackbox into "next/previous song" switches.
The bank layout would be omitted completely, and you would simply work with a setlist. Each song in the setlist can trigger any set of MIDI commands.
..."
A suggestion would be to have hold function assignments like on FM3 so to be able to have 4 commands under the feet (like pause or stop), or even TRS inputs so one may connect 4 switches or 8 commands, plus the 2 control pedals. I hope it works out one way or another. Wait and see.