Sorry for taking so long to respond. It's taken that long for them to arrive from a seller on Ebay but finally I got the new remote and extender today.

I've got everything working perfectly in standalone mode.

I did have a problem with one of my functions which would crash one of my remotes (but not the other 2 with the same configuration) Turned out this particular function was labelled as a legacy code and looked different, that code worked fine using the devices IR emitter but not with the extender. All sorted now though.