SNS3
I confirm that the P180 forward wing is just that, a forward wing , and as such it also been patented. Its main purpoposes are twofold : increase enormously the CG envelope, and ‘protect’ the stall , as it is stalling at a lower alpha than the wing, thus kindly giving a nice pitch down. I agree with you that normally flutter (structural resonance) is more connected with high EAS, but nevertheless, for certification purposes , it should verified free also at limit Mach number.
However I disagree on the Max TAS issue : this is normally referred to level , stabilized flight, and I am pretty sure that 400+ KTAS cannot be reached in cruise condition at
FL 410 – unless you push the aircraft with more powerful engines – the FL at which MAX TAS occurs in sustained level flight is between FL260 and FL270. At this speed/altitude, you also cross, in the flight envelope, the MMo number, which is 0.67 for the Avanti I (I do not remember the value for Avanti II, I suppose a little bit higher).
Kind regards
Daniel