[Darryl Ramm]

..other than Ozone...

Lets pause there and wonder why you are using Ozone and talking about latency. Ozone is a high latency mastering suite. You should not be using it where latency is an issue.

You want to give some clue what "go back to 2001" means? Clearly describe you doing with what. Are you using the Hybrid Engine? Are you talking about monitoring latency or latencies seemingly not corrected by delay compensation? Where are these plugins inserted (master bus?) Is plugin delay compensation enabled?

What latency are you seeing in samples (ideally measured to a sample or so accuracy) and at what sample rate. You should be able to work out how to use Pro Tools to measure any latency you are experiencing. And say what HW buffer size are you running at (for any native plugins). What additional latency do you expect from the plugin/plugin chains you are using... (from observing the latency compensation values displayed in Pro Tools and/or from the plugin documentation.). Often accurate measurements of latency will give a clue to what is going wrong. Including effects from the HW buffers, inappropriate plugins, or possibly stuff related to know bugs in Pro Tools latency compensation (esp. suspect if you see delays of 1k, 2k, 4k samples).