…I do not agree with you…
That is your privilege, but, with respect, you are still wrong.
...Diving more than 5°=8% would reduce your speed by increasing drag significantly...
I'm not sure what you mean by that.
If you mean that the increase in drag will not allow the aircraft to accelerate, then you are not correct.
Whilst the total drag may well increase in a dive, the steeper the angle of the dive, the greater the acceleration and the faster the aircraft speed, right up until the point the aircraft achieves terminal velocity in a vertical dive.
Only at that point will the aircraft not accelerate any more due to drag.
…reaching conjunction altitude and VMO before exceeding M1.0….
Again I’m not sure what you mean by that, but as we are talking about deliberately exceeding MMO, why worry about exceeding VMO, which is probably less dangerous, though still stupid?
…Saying 8%, would be 1.6kt/sec, which is 96 kt/min, but at this speed, you'll lose 5.000ft/min…
And so easily exceed M1.0 long before reaching the tropopause, thank you for doing the maths to prove my point!
You can also read the post by 777236ER
to see his calculations.
I must caution however, against trying to use simple maths and subsonic aerodynamics in the transonic and supersonic regions.
Many pilots died, and many aircraft were lost, whilst scientists discovered the special laws applying there. It is a highly specialised flight regime and virtually everything changes there, which it was why it was called the Sound Barrier
for so many years.
Je suis sûr que votre Anglais est bien mieux que mon Français, mais je voudrais vous souhaiter un Joyeux Noël.