Applying gain and improving audio quality . . . ?

Thanks to all for sharing their knowledge and opinions -

A case scenario . . . Lets say you have a song with 20 audio tracks that were recorded much too low.
One way to boost gain across all tracks is to select a gain plugin (or EQ plugin) and apply it equally at the insert path of each track.
I’m being told that this method will significantly improve the quality of the audio.

A 2nd way is to select all events in the project window, and apply gain using the Gain processing dialog in order to increase the gain of all events equally.
My question is . . .

Will this 2nd method provide the same audio quality improvement as the 1st method?

[I hope so because my 10 projects with audio tracks that were recorded much too low are in Cubase SL2 which can only boost the gain by way of the 2nd method - so I’m hoping that that method will provide the same audio quality improvement as the 1st method?]

Can anyone shed any light here?

won’t make any difference either way, just louder tracks, same result, louder tracks. Doesn’t improve audio quality, just makes them louder.

Thanks Split
This will make finishing up these songs a whole lot easier
Appreciate it . . .
David Main