Would lowering 'xGainMultiplier = x' in persisent.txt lower its values in-game?

[ActuallyImad]

By that I mean by changing the lines in persistent.txt:

Science/Funds/RepGainMultiplier = x

would their values be changed in game? In my experience, I haven't found anything that I can't change in persistent.txt, but I remember trying it long ago before 1.0 and I don't think it worked, just that in my current career mode, science mutliplier is set to 160% and now I'm doing interplanetary science I'm finding the rewards are too big, but I do wan't to keep this save, as it's my most complex space program so far.

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It works! The reason I thought it didn't was because last I tried, I looked at contract science rewards, which wouldn't change despite what I'd done in persistent. This time I lowered it, and before changing SciMultiplier, I used a science instrument, reverted flight & quit to main menu, changed multiplier, then wen't to the same place and used the instrument, and it was 60% lower, so it worked perfectly.

[Daid]

It works, but rewards for contracts won't change that instance, they will only change for new contracts.