Heya -
yes, your observation is correct: the XB-70 used to lower the outer wing section 65 degrees for speeds from M1.4 to M3+ with several benefits (summarized in the chart below)
The outer wing section of the 3D model can indeed be lowered by 25 and 65 degrees, but currently the effect is a purely graphical one
The following two images, taken few seconds one from the other at M3.1 and approx 73000 ft show the airflow visualization around the wing and body with folded and un-folded tips, the different position do not affect the flow in any visible way and it appears to be identical between the two situations
My understanding is that MSFS aerodynamic calculations take in account the airplane geometry as defined in the flight model file, but not its 3D shape
I tried to ‘cheat’ the flight model by deliberately reducing the wing lift at high Mach velocities to compensate lowering a flap surface (to simulate the compression lift) but so far without success