Background Mask

For others who may come across this issue.

Background Mask defaults to a 1.5 border between the edge of the text and the blockout rectangle. For some cases this will be too big, causing the blockout to interfere with nearby text. Also Bricscad V12 will crash when attempting to change this figure below 1. The upshot is that a very small margin can be created by using anything above 1 - for example 1.1