Do large telescopes, especially plans for the LSST, avoid saturation artifacts from the brightest stars and planets? If so, how?
Large surveys don't usually bother to do anything about bright stars saturating the images.  It is more trouble than it is worth to deal with, and these kinds of surveys are designed to study much fainter things.  The data from bright stars are just unusable.  If an astronomer really wants data on a bright star, they can go to a smaller telescope and/or take their own observations with filters/apertures to reduce the light from the star going through the optics.

Here you can see one of the many examples of bright stars saturating the detectors on the SDSS survey: http://skyserver.sdss.org/dr15/en/tools/chart/navi.aspx?ra=81.5049695271329&amp;dec=-5.52153697792986