We fought everything trying to be stubborn and use AOIs. It wasn’t until I did some serious testing and reading across multiple scada systems and in depth study and testing with Ignition that we changed to a udt and aoi system. 95% of our base tags are now in udts. One one specific system that has 150k tags plus we went from 90-103% load factor down to 10%. That was enough for me to know that AOIs are going to give you a bad time. Do AOIs work? Yep. But it is a shakey foundation to build a large system on, in my opinion.