Get (rent) yourself flicker free lights with a ballast in the countries you are traveling to. You shouldn't have any problems. Yes, I have shot in 50Hz countries with the HVX.
If you don't have the resources, then you can simply get 50Hz bulbs for your current lights, which can be easy or very hard to get. What I like to do is buy the universal power strips over in the country you are currently in (it's a power strip that accepts almost any kind of outlet and if you buy it there, the end plug will be correct) and plug your domestic lights into those. (No adapters needed) You can put a lot more on a circuit as you have double the voltage of US power. It's a wonderful system. Any modern electronics you might bring should have a dual voltage power supply. Check before trying it. If the power supply says something like 100-240V you're good. If you have a couple of the universal power strips I mentioned, you won't need adapters there either. Best to get a little universal outlet adapter kit or two just to be sure.