Way to set start frame of animation clips from start frame of NLA tracks

[Rodg88]

as per previous chat, to offset the start of an animation.

[Rodg88]

i think it was to allow you to have animation clips start before the actual animation, to have some frames with no movement. the issue being some animations needing empty frames at the start, and that was somehow hard to achieve? I think it is probably able to be worked around though.