Those markers may actually be irrelevant for the tracking, because they are very small and are meant for different frequencies. ADS-B also doesn't come into it,

Those markers may actually be irrelevant for the tracking, because they are very small and are meant for different frequencies. ADS-B also doesn't come into it, if they designed the system or demonstration correctly. More interesting would be whether those planes actually had the full stealth coating and various other "stealth settings".