That’s 10.5% messages stronger than -3dB
(If you are running the adsb-receiver project graphs the display of those messages is bugged, for correct logging see (Optimize Gain - which would you chose - #174 by wiedehopf))
If you are concerned about close in traffic lower the gain to 33.8, otherwise it’s probably best to leave it.
Same as above if you have low flying planes disappear when they get too close to your receiver then you can decrease gain.
You might lose range but that depends on your setup.
@makeitwrite if you want to fix up your graphs/logs as well see the following post in another thread:
(Optimize Gain - which would you chose - #174 by wiedehopf)