Sorry I forgot that even when overriding a surface, the GO will override the entire element and not just the actual surface involved.
There is one other option in 'Project Preferences > Legacy'.
You can set it to 'Use legacy intersection and surface methods for model elements'.
This will give you the old 45° mitre at the corner but will also prevent building material surfaces (you have to set every surface yourself) and Priority based Connections will no longer work.
And you will still have the problem that the GO will override the entire element.
Barry.
One of the forum moderators.
Versions 6.5 to 27
i7-10700 @ 2.9Ghz, 32GB ram, GeForce RTX 2060 (6GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11