Never had a problem with a DGS or FO training guy. Had 2 line Captain LCA pull stuff out of thin air with "this is how I do it, so it must be right" procedures that had to be agreed with, or thou shall not pass implications. Fortunately both times my Captains took up the issue, so I let them discuss among themselves ... As an FO my only opinion is "no, I don't need to see that again" and "yeah, I'm good with going home early."