For those, as me, who'd love to play a 16.2 TS game during A17.1 TS development, it's possible.
A guy explained very well how to download a previous version of 7D2D, even if not proposed in Steam, it works wonders :
https://7daystodie.com/forums/showthread.php?106460-Guide-How-To-download-almost-every-past-Steam-version-of-7-Days-To-Die-from-Steam
I'm now starting an new game, I'm so happy ^^