WinForms Designer Hangs on a form with a large number of controls as of VS 17.5

Environment

VS 17.5.1

.NET version

.NET 6

Did this work in a previous version of Visual Studio and/or previous .NET release?

The problem does not exist in VS 17.4

Issue description

When opening a form with 2700+ Telerik controls and simply trying to save the form, VS hangs. The CPU varies but goes to 90%+ and the memory used climbs to use all available (64 GB), The form never saves (tried up to 8 hours). This did not happen under VS 17.4.

Steps to reproduce

create a form with 2700+ Telerik controls and open in the designer then try to save the form

Diagnostics

unable due to the hang.

[elachlan]

Is it even possible to have a form with 3200 controls? Winforms has a handle per control, you will run into handle starvation and receive OOM errors if you add much more controls. Moving your app to lazy load controls would massively reduce your memory/handle usage.

.net framework had the same issue, I moved to lazy loading because the designer was painfully slow for some of the larger forms with 10+ tabs.

That being said, it would be nice if the designer could handle it. What is the minimum number of controls that causes the issue?

[Philip-Wang01]

Changed the status of the feedback to under investigation and verified this in a different environment. In VS 17.4.5, opening the MainForm about 90 seconds and then saving the Form after resizing it takes about 30 seconds. In VS 17.5.1, opening the MainForm about 90 seconds and then saving the Form after resizing it, VS is not responding. In VS 17.5.1 + vsix, opening the MainForm about 90 seconds and then saving the Form after resizing it takes about 300 seconds.