Taxiway lights have been confirmed to be in development during the staff livestream not too long ago, as well as Tyler closing the topic as a result of this confirmation. As always, Infinite Flight doesn’t provide any timeline for the development of these features, but it’s good to know that it is already in the works and hopefully shipped some time soon.
If you want to read more about this, I suggest you take a look at Tyler’s reply to the closure of this topic as that will be the best source of information at this point in time.
As for volumetric lighting from the lights of the aircraft, such as the landing lights, taxi lights and turn off lights, the feature request is still open, and nothing has been mentioned by the developers. If you wish to see this feature come, I highly recommend you take a look at the request, and drop a vote if you are interested in seeing it come to fruition.