At present the FIR ID's aren't displayed (or I can't find 'em!) and one has to look elsewhere.
eg Flying Calais to Koblenz one crosses from France into the Belgian FIR (EBBU) thence into the German(Langen) FIR (EDGG) and the reversed route to show change in FIR entries (in this case Germany(Langen) (EDGG) - Belgian (EBBU) - France (Paris) (LFFF).
Is it even possible?