I'm doing a few long trips (out of Sydney) usually with 10-15% hard packed dirt. Using Vee Rubber medium weight tubes in Conti TKC 70s. I carry them as spares as well.
Recommended by Balmain tyres who do a few adventure bikes and I've had no issues. And no balance issues. Can get the 18 for the rear without issue. On my second set of tires post the OEMs and swap tubes when I do the tires.
I don't tend to play with tyre pressures just leave them at 200/250 kpa for the road and hard packed dirt. Find that on the dirt I'm comphy at 100 kph.