The sampled material gets +12dB due to the internal gain structure of the OT.
There is a passage on the manual.
Keep in mind that is an internal gain boost, i mean …the file is not affected…Only if you (EDIT tab of AudioEditor) Normalize;Cut/Boost there…then your file will be permanently changed.
And all depends on what you need to do with the sampled material.
If you want only to digitalize vinyls, then Normalize only and get that fiel from the AudioPool.

About the NoiseGate…i dont use it . Because if i need clean audio i will strip it in DAW.
I prefer to have noises instead of not. Sometimes they can gift you some nice sparkle carpets if boosted properly.