Congrats on the 15. It's my next purchase too!
The lansky will cause your angle to change along the radius of the recurve. It has a fixed point where the knife is. The contact point of the stone on the blade is not fixed. This causes the tangent (hope that's the right term) to lengthen or shorten as it follows the blade, obviously raising or lowering your angle. You can watch this happen if you look at it from the side.
Ive never been a fan of these systems for this exact reason. You can adjust your technique to accommodate somewhat, but during the learning curve, you'll end up needing all the core knowledge you'd need to freehand sharpen anyway.
I hate when people recommend the OP do something they didn't ask about, but I'll be That Guy and recommend freehand.
The reasons are numerous:
You have one of the easiest knives to work with. Nice wide bevel, with only one side to worry about. Simple, responsive steel.
It's cheap and simple. A diamond rod is all you need.
It'll bypass your learning curve. You're going to need the same knowledge base to make your Lansky work well. Then have to learn the muscle skill after that. Why not learn both at the same time?
It's FAR quicker. Both the learning, and the process. Even if you refuse to learn the muscle skill to freehand, and went through all the frustration and time learning how to make the Lansky work, the actually sharpening process will still take FOREVER, due to all the clamping, unchanging, checking, reclaiming, etc. By hand, it'll take minutes.
It's satisfying and empowering. Once you can do it, you can upkeep your knife anywhere, on nearly any surface. No more crutch.
FWIW, I'm not parroting any of this from stuff I read on the internet. Every single thing I've said here is personal experience.
Again, apologies for being That Guy. But if you're on board check out Emerson's tutorial on the website, then head over to Maintenance, Tinkering, & Embellishment here, and read the stickies.
Hope this is something to chew on. I'd just like to help you save time and gain a universally useful skill that's truly cake to learn.
Good luck.