For anyone else with an RNS510 (or possibly RNS310/RNS315), I've been attempting to do some more digging on this.
I tried simply selecting Classic FM (Inrix) in the TMC settings, but only Heart (Trafficmaster) shows up despite me being able to tune to Classic FM no problem. It's interesting that Heart still shows as a TMC-broadcasting station, despite that service being turned off.
I also tried plugging in OBDEleven, to see if I could identify anything that looks similar to the coding options people have found for the MIB units. No such luck as far as I could see, though I'm not an expert - it might be that there are some bits that need to be enabled somewhere which aren't obviously labelled. If anyone with VCDS sees any options I'd love to know.
I suspect this can only be resolved on the RNS unit itself however. I have RNS Manager software, which doesn't seem to have any TMC-related options. I know SetConfig is a more advanced tool but I don't have that.
I do have a spare RNS510 with a minor fault or two, so I may pull the HDD out and see if I can see anything in the files which could relate to TMC - I'm hoping for a slim chance that it's like MIB, in that Inrix TMC is there ready and waiting to be used, if the unit is configured to do so. But I don't hold out much hope.
I'll post back here any progress I make with the RNS510 in case anyone else with one finds this thread 🙂