Ok we're mixing the meaning of the words here now.

Yes it buffers data, but it does not buffer commands.

tengizk said that is you send a macro, the TSU all packs it into one datagram and sends it to the RFX, therefore the RFX must be able to male delays in the execution of the IR sends (a very trivial thing in microcontrollers).

Ok to reuse the RFX in case you TSU dies is an option I have not thought of.