Thanks for your suggestions.
1. I tried with the large button size, 24, as you suggested, but the buttons are only very marginally larger - see attached.
2. Re the window pane size, I also tried via Windows Control Panel / Display to decrease the font size, as I had already set it reasonably high, as the fonts were too small in excel, word etc. However, changing the text size down, made no difference, ie words are still cut, as per my image last post. I exited and re-started the CAD, but this changed nothing.
So, it seems, we are unable to control this within DoubleCad or outside of it.