For those looking for a more robust QOS solution for large network look into LibreQoS. The product is primarily for ISP's, but there are are use cases for other types of networks with high number of clients that require reliable service. It works well with OPNsense and its QOS implementatiom provides superior performance over OPNsense built-in traffic shaping/AQM solution. I find that FreeBSD's QOS solution doesn't work well for my use cases and the performance is not as stable. LibreQoS is more reliable.