The Trek/Bontrager mounts use the accessory bolt holes on the bottom of the saddle. Not all Bontrager saddles have this. If yours's does not, the Anatra will still work with it.
The kit for Topeak MTX Beamracks won't interfere with the quick release saddlebags and when properly mounted, cannot tangle in the spokes if the device somehow comes off of the mount while riding.
All kits include everything necessary to mount the Garmin Varia or a GoPro compatible device to the bike (the Topeak kit is for the Garmin Varia only). No additional tools or threadlocker is required.