If running Windows, there shouldn't be an issue with installation and normal operation.

If, by compatible, you mean the touch-screen aspect of the Surface series, I have no idea—don't own one—but suspect not. I recommend downloading the demo of 26 to see for yourself.

There is/was a notation app designed for the Surface Pro to take advantage of the touch-screen. I don't recall the name, no idea if any good nor if it still exists. If it's still around and has decent MusicXML implementation, it might be something to check out.

Along those lines, I and many others use Notion for iOS on our iPads as to sketch ideas (literally) — some even use it on iPhones. Pretty good and $15 in the App Store last I checked. It has never been ported to Android much to the chagrin of those users (there is a Notion for Android but it isn't a notation app). With the basic iPad going for $329; it and Notion supporting the Apple Pencil, might be worth checking out if your goal is portability.

Hope this helps.

Mike H., have you tried the handwriting module for Notion? I have no need for it, but I bought it anyway. It is truly cool!

>have you tried the handwriting module for Notion? I have no need for it, but I bought it anyway. It is truly cool!<

Yes, that's what I was referring to. It's much improved over the years. I can't imagine using it on an iPhone but I've heard that some do. It will be really interesting to see if that will allow an iPad to be used for handwritten note entry into Notion 6 over Catalina. 

I can't stand the workflow of Notion 6 but its MusicXML handling is better than most (talkin' 'bout You, Sibelius, MuseScore, Encore, Dorico & Overture!) assigning/mixing VIs is a breeze. So I treat it as a translator app and never do any creating in it. For the $79 crossgrade, it has paid for itself many times over. If Catalina lets one input notes directly to the Mac through Notion for iOS, I expect that to be huge.

Back to the OP, Notion 6 does support handwriting on the Surface. Again, I don't know how well. If like I, you don't care for the workflow, you can send it to Finale via MusicXML. Notion and Finale both have it implemented fairly well — good enough for me, at least.

I'm a big believer in using the tools I need to get things done.