I learned the Workman layout before getting an ortholinear keyboard.
It was slightly more difficult for me to switch back to qwerty when I was still using a traditional staggered keyboard to type workman, especially when I was still getting comfortable with workman.
I wasn't really worse at qwerty than before: I just felt extra uncomfortable with the context switching.
Now that I'm exclusively using an ortholinear keyboard to type workman, I'm back to my original comfort level typing qwerty on traditional staggered keyboards. I don't enjoy it, but I don't really think about it either. Context switching went from a mild nuisance to completely effortless.
I can't speak to the particular 34-key board in the OP, but I've been using a Colemak 60% (HHKB) at home and a full-size QWERTY at work for a few years (after using Colemak almost exclusively for a few years before that) and I can jump back and forth with no trouble at all. It was a little awkward at first, but that was when I was just learning Colemak and had never properly learned to ten-finger-touch-type QWERTY.
I've typed Dvorak for years on staggered rows, and retained my ability to switch back to Qwerty at ~70% of the speed. I just switched to staggered column 58-key Dvorak though, and I have noticed it takes me a minute to go back to staggered row on my laptop keyboard in either layout. I think it has more to do with the key positions than the layout.
It was slightly more difficult for me to switch back to qwerty when I was still using a traditional staggered keyboard to type workman, especially when I was still getting comfortable with workman.
I wasn't really worse at qwerty than before: I just felt extra uncomfortable with the context switching.
Now that I'm exclusively using an ortholinear keyboard to type workman, I'm back to my original comfort level typing qwerty on traditional staggered keyboards. I don't enjoy it, but I don't really think about it either. Context switching went from a mild nuisance to completely effortless.