Tracking marker inbetween-data

Is there some way to use the keyframe inbetween-data when doing motion tracking? The only behaviour I get from my markers is that they jump from place to place between explicit user- or tracking keyframes, but I would often find it VERY useful if they moved smoothly from point to point.
There are linear inbetween-lines in the graph view, but it seems to only be a visual aid to judge stability.

I mostly want this behaviour to help out with manual portions of tracking, but it would be great as a guide for the automatic tracking as well. First do a quick-and-dirty manual pass, then have the search-box follow it as a basic guide.

But first of all - maybe I’m just missing something more or less obvious?