I have done tethered launch with all BWS sizes, it works ok. Not as stable as the other kites I've used (Ocean Rodeo rise, Cabrinha switchblade), jumped around a little, but worked. I had to put a sandbag on wing tip to keep it down -- and in one launch, found it wouldn't go with too much weight on wingtip. Removed it, kite jumped around a little, but didn't launch until instructed.
I did have one scary moment though, trying this with my 6m in gusty 30kts on a super narrow sketchy launch site. While setting up, I didn't notice the wind had shifted nearly 90 degrees, from NE to SE, so it was accidentally super hot. When I turned the kite over to set it up the kite on the carabiner, it put me on the ground so fast I didn't know what hit me....like getting punched in the face, when you don't even see it coming, suddenly you're just down seeing stars. I was very glad to be wearing a helmet that day. A sore hip and hurt pride only. And more respect for small kites in high wind = big power.
Yes, doable, but be careful.