When entering chords, if I enter more than 32 the font size changes to about half size. Not good for my old eyes - is there a way to increase the size back to the default size , even though the number of bars is greater than 32 ?

What version of BiaB are you using?
For 2016, you have a number of adjustments. Options > Preferences > Display:

Yes, the adjustment for more measures is dynamic. This is normally a feature, but you make a good point and you should set the rows (and/or fonts) as shown by VideoTrack. You can also do this if your version is older; just write back for instructions.

Many Thanks for the advice - That has made reading the chords so much easier.