Crash bars are likely to be a bad investment on the 790 Adventure. Most (all?) of the crashbars mount to the fuel tank mount since it’s the only frame mount available on that part of the bike. This mount is not designed for any kind of force applied to it, it’s just here to hold the fuel tank in place. The couple of welds holding the captive nut are so light they are known to give in just by tightening the bolt by hand… There are multiple cases where the crash bars bent the mount, broke the part in two, and even cracked the tank at the mount.
In addition, due to the design of the bike there’s no frame at the bottom. Crash bars are being tied into the engine, skid plates, fuel tank, etc. They look the part, but in case of crash they will damage the parts they’re attached to.
All that to say that the consensus seems to be that crash bars are unnecessary on this bike. The fuel tank protection are all the protection you need, they are intended to be a fuse and replaced once dinged.
All those warnings will not stop third party to make crashbars, and people installing them. But do check where the crash bars are anchoring to.
SW-Motech have low bars available. See this review.
Outback Motortek are making crash bars, high and low, with optional bottom plate. See the video.
Touratech made a video with a lot of stuff visible on the bike (crashbars everywhere, luggage galore, headlight protection, hand guards). These are slowly starting to appear in their catalog (crash bars are €240 in your choice of color: metal/black/orange).
Hepto-Becker has crash bar in black, orange or metallic finish (Those have been reported to have to be removed for an oil change as they are in the way).
Metal mule released crash bars that protect the tank lobes. £140.
There are more, there will be more.