Having dragged bits and pieces from my studio along with me on my travels for years, I’ve lately settled with my computer, a pair of cans and a midi keyboard similar to the one you’ve gotten now. I never managed to be any productive when I tried to set up a makeshift studio with hardware when on the road. I have many thoughts on why, but I think the main reason is that as I couldn’t bring all of it, it basically ended up being a “new” studio, with a completely different workflow than what I was used to. So it had to be relearnt every time. I’ve never travelled as much as you do though, so this could possibly be a different story for you. But one thing’s for sure: you’ll have an easier time through airport security with what you’ve currently settled on than with loads of hardware, cables, interfaces, you name it. Speaking from experience.