Implicit header?

Hey, has anyone figured out any options for an implicit header?

I am working to communicate (RAK11720) with a legacy system that uses some HopeRF modules. SF=6, BW=62.5k, fixed payload size, implicit header. I see in a topic from Jan, 2024 that this isn’t an option in RUI3 at this time. Just curious if anyone else has figured out a way around this limitation yet.