Point to multipoint user throughput

Hello all! I’m a total newby on the specifics of the LoRaWan protocol. I do understand RF networks though, having worked 20 years as a PHY layer designer of a RF network for public safety. I tried to confirm from the specs if LoRaWan would work for my specific application, but I would need the wisdom of the experts here to give me confidence. What I’m trying to do is a broadcast system (point to multi-point) where the master would register the remote units, but transmission would be without acknowledgements since the BW would not allow for enough units.I have no concern for the RF link reliability since the band used (915 MHz ISM) and the range needed (<500’) is no problem. What I’m concerned about is 2 things. 1- Is this broadcast, no ack mode possible in LoRaWan? 2- What would be the maximum user throughput in that mode?