Anyone know if boosting the vibrance using a vibrance adjustment layers is the same thing as just increasing saturation?
No, Vibrance and Saturation are slightly different.
They are not remotely the same.
If you've never read up on this (Google and the Photoshop documentation are your friends), a simple test to compare this would show you in a matter of seconds.
I won't be so rude as to use LMGTFY, but this might help
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