The whole question of logging time is according to which piece of paper you are trying to get...
Is "IFR time" usable against anything at all? I don't know. Maybe something in the ATPL, but which ATPL?
Solo "instrument time" is usable towards the FAA IR, to a limited extent. One has to do 15hrs dual training. In practice nobody will have the slightest chance of passing the FAA IR checkride, never mind the oral, unless they have way exceeded the logbook hours requirements. What usually catches people out (on logbook requirements) is specific stuff like the 250nm x/c with 3 different approaches - some examiners require them done on the same day, some are happy if they are done in the context of a long trip somewhere.