The 'Stargazer' looks to be the same 'slender delta' wing design as the Concorde. The problem with those was high take-off and landing speeds - and so susceptibility to foreign object damage, not to mention the need for very long runways. As a private pilot who’s flown in the Concorde (as a passenger) I found the long roll before rotation medium terrifying (long story short: was accompanying a relative who’d been involved in WWII era flight design to/from the Paris Air Show in… 85 or 6).

I would have hoped for a different wing design. Back a few decades when the Concorde was flying, something like a swing/retractable canard would have made for an unstable, hard to fly / unsafe craft - with manual controls. But look at the forward-swept-wing fighters (e.g. Grumman X-29, Sukhoi SU-47) for examples of how inherently unstable craft can be made quite flyable with computer assistance.

Also, $50M sounds like a lot, but it doesn't seem nearly enough.