I have full blockchain on some external drive, and any operating system can easily read it, if you point your Bitcoin Core into the right directory
Did you split the data directory into different drives to improve chainstate access speed? just figured
here that splitting can help the access speed of the chainstate especially when the data directory is stored on a magnetic drive. Though it's a good advise to copy both files, but, in some cases, it's not the only possible alternative.
Or is there a simpler way to do this?
Pruning can be simpler and wouldn't require you much procedures or explainations, you can add prune =550 to the bitcoin.conf, I'm suggesting this because it seems you are not abandoning the windows OS entirely to use linux to run your full node.