How to get HtmlDialog to resize without flicker?

Developers Ruby API
4

I run Windows 10 with Nvidia.

SU 2017 WebDialog - does not flicker but is 4 times slower than WebDialog
SU 2017 HTMLDialog - flickers

SU 2018 WebDialog - does not flicker but is 4 times slower than WebDialog
SU 2018 HTMLDialog - flickers

SU 2019 WebDialog - does not flicker but is 4 times slower than WebDialog
SU 2019 HTMLDialog - does not flicker