Hi Paul. You are not going to find that information in the simple manner in which you (and the rest of us!) would like to see it on a Peplink router – or much of anywhere else. There a myriad of factors that govern throughput – bandwidth, modulation scheme, signal quality, on-channel signal strength (not necessarily RSSI), back-haul capacity, etc.
There is a ton of information available in the public domain regarding frequencies and bandwidth. I can’t see where you’re from, but here is an example of such a source for the USA. Everything else being equal, wider bands are “better” – but not always so.
Having said that, your shiny new Cat18 router should serve you well. It’s designed to make the best available use of “what’s out there.”