Without sounding disrespectful I personally avoid Steam, Brightlocker et al because my F/OSS OCD chaffs at the thought of my "stuff" being chained to third party.
Admittedly, the kickstarter said nothing of making the game beholden to the Steam platform:
BOXED OUT - Get a signed box and access to the Proving Grounds level
+ All REWARDS from the BE A LEGEND tier
+ Any new maps or ships introduced for 1 year from end of Kickstarter campaign
+ Personal in-game logo created together with our team
+ Signed box copy of Descent Underground
+ Exclusive access to the PROVING GROUNDS: A level to test weapons and new ships along with our QA department
+ Gold and Diamond Campaign ribbons in forums
+ 11,000 Company scrip
... and I do not regret backing the game in the least, just looking forward to actually being able to play it someday.
Has there been any conversation about when the boxed game is released if it will be required to call home order to be played?