The two aspects that are causing confusion - in my group at least - are stacking of Boon/Banes (or the lack thereof) and when 'hardwired DMs' are listed instead of using Boon/Bane. Both seem fairly arbitrary rulings.
In the former, the blanket 'only one Boon/Bane may apply' is awkward because it has no gradation. Multiple factors could apply and be at varying strengths. Players keep asking about whether conditions earn boon/bane, whether they stack and/or cancel each other out? If you introduce a rule like this, we should expect players to test it out - and referees aren't given much support to deal with this issue as it stands. As with the way DMs used to work, why not leave it up to the referee to justify how many boon/bane dice apply to any situation? Why stick with just one?
The counterargument is that the roll becomes almost redundant at the upper end of a Boon/Bane pool. I get that, but the same could be argued for high level DMs too. If we are arguing for Boon/Bane pools of five extra dice, say, then that is surely the equivalent of +/-10 DM (but without affecting the range). For me, the uppermost range that I could possibly envisage, in a practical sense, is actually more like three extra dice (equivalent to a +/-6 DM), and more likely to generally max out at just one or two (equivalent of +/- 2 or 4DMs respectively). One, two or three (extreme case!) boon/bane dice does not seem mathematically excessive to me - and the range stays the same regardless.
The latter issue is the killer though. If we are going with Boon/Bane then the various 'hardwired DMs' that are scattered throughout the book definitely still need to be looked at. Rather than listing a DM for bad weather, for example, then this should be edited to a Bane. As it stands, the Boon/Bane rules still lack clarity to me (and my group) because the game itself doesn't seem to have made up it's mind on its own rulings. It still needs work to be worth including in the core rules.