2,000 Mercury on stock. Wow. This looks bad to me. You can say they are "listening to the market", but its clear to me that if they had enough orders for Jupiter + Saturn they wouldn't do the additional work required to develop and sell a different, smaller unit, opening the preorders for it in a record time.
IMO, this only means they didn't get enough orders of the previous units. This is starting to look bad.
The design of the case and PCB is the same as Jupiter/Saturn, just 1 chip rather than 4. So, it's basically zero extra design. Just a way to sell more overall units. Perhaps a 2nd chip order, as it's scheduled to ship in October.