I'm a bit upset about the 18 hours thing because it makes it NEAR impossible to complete the challenge log unless you pay money. Of course, the challenge log gain is minimal but it's something. And for those completionists how can't afford an extra retainer it must really suck. That said, reducing it to 4 hours is silly. It's such a big difference that you almost seem spoiled for asking that, haha.

I would suggest adding the OPTION to change it from 18 to 12 BUT increasing the venture cost to 4 or 6, whichever SE deems more balanced.