Thunderbolt 3 Support Is In Great Shape For Fedora 28
This has been part of their goal of having secure Thunderbolt support where users can authorize devices and/or restrict access to certain capabilities on a per-device basis, which is part of Red Hat's Bolt project and currently has UI elements for the GNOME desktop.
Red Hat, as usual, has been doing much of their work upstream and most of these improvements can be found in GNOME 3.28 that is already shipping and the default desktop for Fedora Workstation 28. But there is a Thunderbolt device area added to the GNOME Control Center that didn't make it in time for 3.28, but it's been back-ported to F28's package. Additionally, Thunderbolt host controller updates is now working via fwupd and Red Hat is still pursuing Thunderbolt device authorization support for use during pre/early boot stages.
More details on this ongoing Linux Thunderbolt security improvements for Red Hat / Fedora via Christian Kellner's blog.