I have successfully run RealFlight 9.5 under macOS 11 / Parallels 17 on my M1 MacBook Air with the display on my 4K60 TV.
The performance is good. I am able to fly using the wireless transmitter with no perceptible lag or issues, so far.
I struggled with installation initially. In order for the installer, RF Launcher, or RealFlight app to launch under Windows 11's x86 emulation, I had to go into the file Properties for each executable and switch to Safe Emulation mode under the Compatibility tab. Otherwise, the installer would crash after extracting files and the Launcher would not start at all. While this is not optimal, and caused the installer to run much more slowly, at least it worked, and I haven't noticed a significant impact to usability. It may be possible to optimize the emulation settings, but I haven't experimented with that.
Here is my configuration:
RealFlight 9.5 Combo with Spectrum DXS and WS2000
Windows 11 (ARM) Insider Preview
Parallels 17 Free Trial - configured for Gaming, running Windows in full-screen mode on external display
macOS 11.5.2 (20G95)
Apple M1 MacBook Air (Fall 2020)
Apple USB-C Digital AV Multiport Adapter
+
Belkin UltraHD High Speed 4K HDMI Cable (2m) +
LG 4K60 HDR TV
+
Spektrum WS2000 + DXS - w/USB device mapped to Windows
+
Apple 96W USB-C Power Adapter