I hope that you get great pleasure using your new SX900.
The SX keyboards are superb and sensibly priced too.
You've made a very good choice, and you'll get lots of help and advice.
Try your Wine emulation by all means, it's your choice, but if you don't get any joy, look out for a
used Windows PC or laptop as I suggested.
Anything with Windows 10 on it will make using all Yamaha files an absolute doddle.
I have an old i7 Dell Latitude E6230 running Windows 10pro that sits near my keyboard. Cost me about £30 off Ebay and works fabulously. I use it solely for my music. Older Dell business laptops are pretty bombproof, they are really very well made, have an ethernet connection, AND, a big plus, very easy to work on should you need to. Swap a drive, or a fan, or add memory etc etc. Most of these new slimline all singing, all dancing modern laptops are not!
Keith.