Hello @Corobori ,
As I know, there are no such options for resizing the Web Forms Designer.
However, does Web Live Preview(Tools > Options > Web Forms Designer > General > Web Forms designer (requires restart) > Web Live Preview) meet your requirement?
I would also suggest you submit a suggestion ticket on our Developer Community – Visual Studio(kindly share the ticket link here for better tracking if you do submit a suggestion ticket).
Sincerely,
Tianyu
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