There is an option by changing Telerik.Forums.Data.DefaultProvider and replacing it in the configuration.
<add name="Sitefinity" securityProviderName="" profileProviderName="Sitefinity" type="Telerik.Forums.Data.DefaultProvider, Telerik.Forums.Data" connectionStringName="DefaultConnection" visible="true"/>
You need to override GetForumsUncategorized method and return the items in the order you want.
Another option is changing the template of Forums control that is located under Sitefinity/ControlTemplates/Forums and rebind the repeater with the order you want to see.
In the first case, where you replace the method, you will change the query for all requests to this method, the second option will rebind the repeater, so you will make double binding.
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