Late to this thread, but yes, they do use 2.5mm plugs and I have asked for them to change many times, but was told it was a cost consideration and, while it's a PITA for us, it makes sense for them to want to sell their emitters.

That said, the output from the hub can be connected to the input of an IR distribution kit, like the ones Xantec, Russound, Proficient and others sell. That way, existing emitters can be used and it decreases the number of adapters needed.