Thats for a reasonable repy.

My idea was for a rebuilt A-10, meaning the design goes back to the
manufacturer. All the real professionals here need to complain of the
lack of adequate fighter design, in my opinion.

Supersonic critical airspeed appears a worrysome thing when in fact it
is a simple airframe stress. Nothing drastic happens. An A-10 is a
slow speed design and the basic idea was to do a cheap re-engine to get
an plane suitable for a fighter pilot.