This is great and all, but they are just snapshots in time. We need total 360 degree coverage of the sun 24/7. Stereo A and B did this great, but when Stereo B failed, it was never replaced.
I wonder if the 4m DKIST on Earth would have higher resolution photomosaic of the sun if it were used to do this one day? Probably. It's field of view is smaller but it can image features down to the high single km scale (~8km) on the photosphere.
The problem with this is that at 10km scale the features of the sun are changing far faster than at large scales. The rows of exposures' tops and bottoms would not match very well assuming a normal raster scan. The higher the resolution the smaller the timespan you have to take the full disk image. And the higher the resolution the smaller your FOV is. It's a rough situation.
I sometimes wonder if we should have probes orbiting each planet and the sun, with the most generically useful sensors, for research that isn't planned decades in advance. But I really don't know if that would be a good investment of scarce scientific resources.