Thank you for writing.
The observed memory consumption is expected since the default theme is loaded as a static resource and this theme is shared between all RadControls instances in the application. Please note that the theme stays in memory until the application is closed. So, if you add a 100 new RadButtons in this form this will not increase significantly the memory consumption in the form. More information about this is available in the following articles:
I hope this helps. Should you have any other questions do not hesitate to ask.
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