I had a standard length PowerFLARM and ADS-B antenna through a hole in the glareshield of my ASW-27. After upgrading to dual long PF antennas that I placed on opposite sides of the canopy with Velcro, I placed an internal L2 transponder antenna in the glareshield hole reaching to just below the canopy favoring visibility to TCAS above and satellites. Being a long way from any big airports, I haven't verified with ATC, but suspect I'm visible to ground installations unless close in above or pointed directly away when my body and carbon fiber will be in the way.