Anecdotally, I did not have too much of an issue switching to a columnar layout - I would give it a shot if you were interested.

I've been using a Moonlander for about a year. I feel like it took at most a week for me to adjust and to attain my current typing speed. I probably type a little slower on it (maybe less accurately too), but my rate is passable (80-100 WPM). I've recently tried a Kinesis Advantage 2 for a few weeks and did not find that adjusting to it was very difficult.

Maybe I'm the odd one out here. Edit: having seen other comments here, I suspect I might be. Apologies for making switching seem trivial.