Where in the registry are Outlook field sizes displayed?

Question

Windows Registry

Hello,
I use Squish to test plugins for Outlook. Squish compares screenshots (one way to check).
In order for the tests not to fail, I need to make the applications identical on multiple machines.
One of the problems is the width of the folders and emails panels in Outlook. The standard width does not fit - it is impossible to check everything, and when setting "by eye", the tests break.
Accordingly, it is necessary to adjust the busbar of these panels to within a pixel. As I understand it, these sizes are stored in the registry, the question is - where exactly?