MCST will get data that is better than on orbit because of controls that can be done on the ground, such as spectral tests. These will be very good data, which will allow very good simulations before launch. It's a continuum. Bits and pieces will come in. Radiometric and geometric data will wait for protoflight because some fixes are not present in the engineering model.
Spectral data are available now.
Ungar doesn't think the team has a simulation plan because they don't value simulation. He feels that simulation fell by wayside as funds got cut. He suggests that a good simulation is a present product which is extremely well characterized and which can recoup variations in an original scene. With this you can have synthetic scenes, simulated scenes, characterize algorithm sensitivity, adjacency, etc. His second point is that emphasis should be on whatever the team needs to have ready now.