This is especially interesting to me because just three weeks ago I traded a 2011 KLR I'd had for 9 years for the ST I have now. I definitely know the appeal, I bought mine because I wanted to do more off-road exploration and it filled that role well during the time I had it. I called it "the tractor", because I would get myself into all sorts of gnarly situations, and I could just drop it into 1st gear and it would simply plow through or over whatever was in my way. Loved that bike. My advice: Armor. For the bike and yourself, because you're going to drop it a lot and probably crash it a few times too. I'm not saying that as a "you don't have the skills" sort of take, I'm just saying it goes with the territory. Barkbusters, metal engine guard, front and rear crash bars for the bike. Motocross or "adventure" boots, thick gloves, and some knee and torso/shoulder protection for yourself. The worst injury I had was hitting some mud on otherwise solid ground through a curve in a trail, I went down at about 20MPH and messed up my knee badly. It really sucked picking that pig back up after that one. Some other incidents resulted in sprained ankles, wrists, cuts and bruises, and back injuries (I have a bad back though). Oh and speaking as someone who put basically every mod there is on my KLR, resist the urge to change the exhaust. You won't get more power, it just makes it louder. And the stock "stealth" exhaust comes in handy when you're exploring, doesn't draw attention.
Anyway, congrats on the bike! I'd like to try one of those current-gen fuel injected models sometime. I had to clean the carb on mine so many times I got absolutely sick of it! I have to ask though, why not just keep both? KLR for exploring, ST for long distance. If I had the option, that's what I would have done.