Just add some cool new achievements, available in beta.
Deus Ex: Revision does that, some data bellow.
start of beta : 14.08.2017
end of beta 14.10.2017
Players tracked by Astats that get "Not so fast J.C" achievement before end of beta 8/11 ---> 72%
(probably more, but they are not tracked) http://astats.astats.nl/astats/Steam_Achievement_Info.php?AchievementID=242&AppID=397550&SteamID64=76561198039374546
Medium daily players for Deus Ex in September --------> 22,4http://steamcharts.com/app/397550
Medium daily players for Baldur's Gate in September-----> 403,5http://steamcharts.com/app/228280
Forecast of extra achievement hunting players during two months beta: 144,1 (minimum)
I know that both games are very different, and have different communities, but it worked once, so maybe give it a chance?
Anyway, I just wanted to help.