Thank you Phoenix.
A big reason why I was considering Ikea’s curved slats was the online comments about how they don’t hold up. Perhaps I should stop my fixation on Ikea beds and look at my other options.
My ideal base would be a little taller, at about 20 inchs. This would allow the mattress would be around 30 inches high. One big attraction about Ikea’s design is that I could have found longer lengths of wood and swap out their shorter leg for a longer one. Ikea is also comparatively cheap for a solid wood frame that I won’t necessarily want to take with me when moving after some years.
A sturdy frame, or something that can be made sturdy, is a plus too.
This thread about bases has been useful, though I didn’t see anything that matches my needs.
In the meantime, from reading the threads, a clean flat wooden floor probably suffices for the very short term.