Like many people, I'm building a Sonex because it strikes the right balance between affordability and performance, with great emphasis on affordability. I'm doing a very basic panel and really like the Uavionix products. The TailbeaconX is a good /cheap way to be ADS-B compliant, which is especially important for me as I fly under a Mode C veil.
To use the TailbeaconX with the Sonex, I 3D printed an adaptor using carbon reinforced nylon and was able to get what I really think is a nice install. Here's a set of pics showing the process that I followed, starting with the finished product.
I should have sanded the 3D printed part prior to painting, but overall it looks pretty good.