Yep, I'll infuse when its a 540 into a 510 of the exact same gun but the low level one had the better roll. And I've infused important exotic armour like Orpheus Rigs or Raiden Flux when they dropped way behind. But other than that I'm just using what drops and am not having any issues completing content and it's a lot easier to advance your power level. Currently sitting on 25 master work cores.