There is no registry key that I know of - but that doesn't men there isn't one.
There are keys for special symbols - East (E), West (W), degrees (°), etc.
As far as I know it is only controlled in the object script.
You will need to open the object and go to the 'Compatibility Options' (version 16 & 17 or 'Details' in older versions).
There you can change the defaults - it will change to a 'Custom' value.
You will need to do this for every door and window and save the library part.
The problem is if you are using Graphisoft or 3rd party windows then these will be reset if you ever update them.
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