I've just done some number crunching to see how much sense the bastion turns per level values make.

• The oft-quoted 6-8 medium/hard adventures per day gives us an expected amount of XP that the players should be getting per day
• I'll estimate on the lower side of things to give a bit of benefit of the doubt for how much people actually stick to that (i.e. not at all)
  • 4 PCs
  • 6 encounters per day
  • the lowest amount of XP that qualifies as a medium encounter shared between the PCs
  • You stop adventuring for the day when you reach a level up so I don't have do deal with fractions of days
• This means that at each level you need the following number of days adventuring at each level:

1. 1
2. 1
3. 2
4. 3 (2.53)
5. 3 (2.5)
6. 3 (2.5)
7. 3 (2.44)
8. 3 (2.59)
9. 3 (2.42)
10. 3 (2.92)
11. 2 (1.56)
12. 2 (1.67)
13. 2 (1.52)
14. 2 (1.67)
15. 2 (1.79)
16. 2 (1.56)
17. 2 (1.71)
18. 2 (1.59)
19. 2 (1.70)

So unless my maths I is way off it seems they expect you to level up every two or three days, which doesn't at all fit with the amount of bastion turns they're asking you to take.