I am just playing around with the Mosaic Planner (Mac OS , latest stable Kstars) and I can see that it responds "erratic" and is not rendering real time.
For example in this picture lets say that I want those panels to go to the centre of the map, I would have to press the recenter button, correct? But if I click it nothing changes. I have to click it and then go and click into the map to see the change.
Then if I want to pan into the map and drag those panels around for precise framing, this is just impossible
Now I can see better performance while panning and dragging those panels, but still with a little lag 1-2s. Probably cause it renders all the background simultaneously.
I have noticed that the frame orientation for large mosaics don't quite match what I expect. If they are meant to wrap the on the celestial sphere in the same way an FOV symbol can 'Lock to Celestial Pole', I find they don't match up. It should adapt for all declinations, but the pattern is more or less the same until it approaches the poles where things get a bit wonky. At the celestial equator, there should be no significant rotation, crossing to the southern sky, the scheme does not work at all in the southern hemisphere which should turn the opposite way.