This is actually not easy to do. IMatch 'scales' the sharpen parameters set by the user to counter softness introduced by resampling the image when displaying it at less than 100%, but there is no golden rule of effective set of parameters. Also, there are limits of how large the parameters for the sharpen function can become.
For the next built I've increased the scale ratio a good pinch - so that most of my test images look 'too much' when viewed ad 100% and at fit-to-window. A medium sharpen looks OK in both scales. Problem is, as always with sharpen, the result depends on the details in the motive, if sharpen was already applied in-camera or the processing application, and the user's individual perception of sharpness. IMatch sits in the middle between the capture and the output sharpening, somewhat.
Let me know what you think about the 152 when it's out.