There are a number of approaches I can think of, and would certainly give it a try. Starting with:
FIRST: Try to copy and paste the keyframes. (I must say that for me this does not always work as expected. E.g. not all settings are copied perfectly all the time.)
SECOND: To pick out one clip to use as a reference to all. This can be a small clip or a larger clip if that works better for referencing. Then set the brightness (and other settings). And then depending on how many clips you have maybe even produce this reference clip so that it is easier to handle in the following step(s). Then do color match with the reference clip as … reference to set the same on the others.
THIRD: try out LUTS to see whether you can get the brightness the way you want it and see whether applying the LUT to all other clips will give the desired results. Maybe there is a LUT available, otherwise it may be possible to look for and import a (free) LUT that has the right settings for you.
Depending on the amount and size, you can do that in one go, or in a number of goes. I would also consider producing all clips (using a high-quality format, at last of the same quality as the source) so that the brightness and other settings are done when you (maybe?) use the multicam?
ColorDirector has some feature too.....

The setting would be (about) one click, the handling is a bit more than one click, but.... 50Gb.... will require some work.