So... I basically updated the existing M2TemplateCata to include the new Legion animations for the Legion character models.
However I now see why I cant get my changes to work the way i want them to. Since i have to remove the MD21 chunk at the front all the time, in case of BloodElfMale_HD.m2 the first 8 bytes, the changes are being pushed 8 bytes away from the correct position.
I guess I will now have to find a way to make it load with the md21 chunk at the start so that i wont have to insert it afterwards again or ofc trying to make the changes at the correct position, however that seems a little difficult since I cant say for sure which exact position I will have to edit.
Just in case that anyone is reading and perhaps wanting to help me, here is the M2TemplateCata with my updated changes:
M2Templatelegion.bt