Ok, Im going with a tooltip which shows sigma and median.
Sorry I wasn't able to find time lately. Let me know whether I should output the details in
1. an overlay on top of the image itself ( although limited number of stats, like Width x Height, sigma as this looks messy )
2. a new floating window with the same stats table (similar experience as in Siril )
3. the existing stats panel itself (which alternates between full image stats to selection stats depending on a button )
Attached Image shows how it would look in option 3.