If you pull the spark plugs out, you should be able to roughly judge the fueling by looking at the colour of the insulator on the centre electrode. Black/sooty would be rich, white/light grey is lean and a slight tan colour is usually the Goldilocks Zone.
I agree that lacking a cat, the exhaust on the 5th gen is a bit smelly compared to bikes with cats fitted (I also have an MT-10 and ST1300).
Are you sure that the hose connecting to the pressure regulator is sealing well? The regulator uses the vacuum from the intake to reduce the fuel pressure under higher vacuum conditions. If that hose is leaking, then the injector pressure will be higher that desirable and more fuel is injected.
The two hoses referred to earlier from the tank are the air vent (skinny one) and the filler overflow (the fat one). Ideally you want the fat one to extend down under the bike so a fuel spill during filling doesn't run onto hot headers (but that could fix your rich-running very quickly!). IIRC the skinny hose just needs to head downwards, its just there to allow fuel vapours to expand out or air to be sucked in as fuel is used. In CA that probably should go to a charcoal cannister if you still have one fitted ( that would be hose 1 in the diagram below).
The 5-way joint is also only relevant if you have the charcoal cannister fitted (CA). The rest of us have the vacuum hoses plugged into stubs on the airbox.