Just to close this post down, Apparently you can use version 3.0 and 2.2 devices with version 4 with the switch set to "Auto" - I have not validated this in the real world but this is what TP-Link...

@John1234 thank you for the comment. I have just re-read the downloadable documentation for the V4 of the MC220L and there is no mention of how/if you can use it with previous revisions. I sent an...

Good day! Can anyone please pass on experiences of using different hardware versions of MC220L Media Converters together. I have a mixture of V2.2, V3.0, and V4.0 devices that I use with TL-SM311LS...