I have been working now with Editor X for several months, with a steep learning curve. Regression issues are indeed an area to improve on. From my experience part of the regression issues seem genuine bugs, which is improving month by month.
However some regression issues are also caused by how margins, docking, padding, grids etc. are set in different units as %, vw, wh, px, fractions. Editor X is quite unforgiving if you don’t get these consistent. For example being able to use calculated grid size is very powerful, but can cause unwanted effects later on. Also when working with grids you need to be meticulous which cell the objects spans. Checking all these settings methodically helps to avoid issues.
The great flexibility leads to so many possibilities in combinations that I don’t think it is possible to catch issues all before releasing it to the BETA version. The more we build and report issues directly to the Editor X team as a bug or feature request, the better they can make the product.