How can classes be removed from panel panes? Is there a way to remove the default 'panel-pane' classes, without creating hundreds of templates for different entities, and while still keeping the option of adding custom classes to panes?
By admin panel. When you edit a panel page, click on a cog of the pane that does not need styles. Check styles. Choose no styles. There few options. I do not remember exactly how it is called. It exists there. Check it ...