Assuming you are correct, that A2001 had to fail in order for Building 7 to collapse, you have limited the possible failure to "walk-off" at column 79, and "extreme sagging", both of which you claim "impossible". Your premise is invalid due to limited choices. There is another end to A2001, the perimeter wall connection, which could have failed.It was a key factor in the NIST collapse scenario - but it did not happen. Without the walk-off of A2001, the collapse does not happen. Therefore, the NIST report does not explain the destruction of WTC 7.
The video simulation has the collapse happening but it uses an impossible extreme sagging of A2001 to trigger the collapse.