There are several questions relating to motion tracker and size/zoom, but I can't quite tell if my question is answered or not so asking it separately.

In order to get a quick/accurate motion tracking result, a size parameter less than full screen is needed. 25% is the default.

After importing the tracking keyframes into a Transform effect, the size of the motion tracking box is somehow being copied into the size of the Transform box. Thus, I get a shrink, or a zoom out that is not intended and I have to edit the imported keyframes manually to restore the zoom to 100%. I switched to Position option to import the keyframes and got the expected 100% sizing back, but now there is an offset somehow being applied instead. One way or the other, I can't get the motion tracked keyframes correctly into the Transform when everything is at constant 100% zoom. What am I missing here, must be something simple?