Well I do "record the actual Audio from Kontakt into" Reaper. I can route the output of the track that Kontrakt is on, to the input of a separate track and hit record when it plays. Certainly RB has that type of routing cabability, right?

In fact it is actally much simpler in Reaper which has a "render\freeze" feature which will save the midi, mute it and put the redendered audio right on the same track. Is that what you are trying to do?

BIAB – 2025, Reaper (current), i7-12700F Processor, 32GB DDR4-3200MHz RAM, 1TB WD Black NVMe SSD, 2TB WDC Blue SSD, 1TB WD Blue, 2 TB SK NVMe, 6 TB External, Motu Audio Express 6x6