That's a clean looking setup. Are those lead acid batteries? It looks like there is more than enough air space in there but I was always told the "vapor" lead acid batteries can release is flammable. Could the inverter being open to the batteries cause an issue? Might be worth a google.
I enclosed my batteries and inverter in bins and vented separately. There are lots of smart people on here to prove me wrong. Just what I have always been told.
Good luck with everything.