Yes it is very annoying, but I don't think it is random, as a particular morph always seems to get the same trackingScale. Perhaps it is some calculation based on the maximum displacement of a vertex, but I am just guessing.

I don't know what you mean by a "binary morph", but have noticed that targetGeom channels without any deltas get assigned a trackingScale of 0.02.

There are a couple of workrounds I can think of, but they are a lot of work if applied to all morphs, and not very elegant. One is just to slave the targetGeom channel to a valuParm channel, then hide the targetGeom channel. The morph will be set from the valueParm, and that can have any trackingScale you want. Of course this method can lead to crosstalk in P4.

Perhaps a better method is to use 'linkParms' to link the targetGeon to the valueParm, this method avoids crosstalk. The linkParms statement goes in the 'figure' section of the cr2, (traditionally under the 'displayOn' line, though I dont't think the position matters). As an example assume the channels 'targetGeom RoundFace' and 'valueParm RoundFaceX' exist in the 'head:2' actor, then the folloing code would be placed in the 'figure' section:

   linkParms    head:2<br></br>                  RoundFace<br></br>                   head:2<br></br>                      RoundFaceX

One might have hoped P6 would fix things like this, perhaps P7 ;)