Panopoly WYSIWYG exclude buttons configurations
Since Panopoly WYSIWYG module does not provide this kind of configuration out of the box, you will need to add additional text formats and WYSIWYG profiles. When configured, export them to your own Features project. If you customize the WYSIWYG profile provided by Panopoly WYSIWYG, be sure to export those using Features Override module (provided in full distro and if using Panopoly Core I believe.)

WYSIWYG profiles merely build on top of existing text formats which have restrictions by roles.

The alternative, however, is to use hook_wysiwyg_editor_settings_alter() and possibly remove buttons based on role, that way.