The native resolution of the 27" 5K iMacs’ display hardware is 5120x2880 so a setting of 7360x4320 is not only forgoing HiDPI, it’s not actually showing all those pixels. There are tasks for which such a high resolution is useful but I would think it would be hard to use that setting all the time.
The 24" M1 iMacs have a native resolution of 4480x2520, you should be able to choose that by Option-clicking the Scaled radio button in the macOS Display System Preferences. I don’t know how many other resolution choices the System Preferences offer for that iMac’s display.
Both QuickRes and Resolutionator have been updated this summer and say they support M1 iMacs. The M1s have different display hardware than the 27" iMacs so I’d expect some differences in the resolution choices. I wouldn’t expect the choices to be significantly restricted, including the “silly resolutions” as Resolutionator calls ones that exceed the native resolution of a display.