On the old VF-19 releases if you pushed the ankles back too far they would forever be a floppy mess that would no longer hold either Gerwalk or Battroid.  Technically this was a problem on the VF-17 as well but it's far more balanced in Gerwalk so stressing the ankles too far one direction or another wasn't really a problem.  The VF, and now the YF-19, are all EXTREMELY forward heavy in Gerwalk.