I discovered an educational video, actually demonstrating DAWs on the SP8, including Reason.
The good news: it actually works. As far as I could understand: much better compared to the SP7.
Of course, there will be a limit to the device performance, but it can handle 64-bit Windows 10/11 software in a lightweight and compact form factor that handles touch input.
ISSUES
1. Reason does not seem to handle a 10-finger multi-touch screen very well, only processing finger #1.
2. Far too much delay when tapping on the buttons of Korg Drum Designer.
3. Extreme knob rotation in Mixer - Reason does not seem to have a Pen mode, needed for touch and pen input.
CHECK
a. How well does On-screen Piano Keys work with a touch screen?
b. Will the internal loudspeakers Mute when inserting a headphone?
c. Support for finger hovering?
d. ???
Surface Pro 8 (i5) - First look for Music Production 11-NOV-2021
This could also be interesting:
Surface Pro 8 Performance Testing for Music Production 4-MAR-2022
The results look very useful already, and the size is light and compact enough for carry-on luggage.
Looks like I'll probably get an SP8 before the end of this year so I'm hoping Reason Studios agrees and can see the potential of this platform.