As stated elsewhere, there's a very recent study [1] on astronaut heart health that's quite relevant. They studied the cardiovascular health of astronauts for 5 years after their return from long-duration stays on the ISS. They were all perfectly healthy.

For one obvious problem with rotation systems, stations need to be regularly boosted. You'll also need to occasionally reboost the local rotation. This sort of basic stuff is already fairly complex with a static station, and becomes exponentially more so with a local rotation going on. Even moreso because you want to be relatively fault tolerant in case of a partial or failed boost. Then you need to compensate for impacts, docking and undocking, and much more.

It's viable and almost certainly a solvable, but NASA is not the appropriate organization to do so. Their risk aversion makes it unlikely that they'll ever be doing much of anything revolutionary where failure could be catastrophic. They're having a tough enough time just trying to recreate what we already did 50+ years ago.

[1] - https://journals.physiology.org/doi/full/10.1152/japplphysio...