What Changes for Poe 3.2 Balance?

PoE's preparing to post the patch notes within a few days, and have come across a few balance changes that Path of Exile wanted to talk about in more detail (and earlier than the patch notes, so there's time to explain and discuss them).
As you know, Path of Exile has substantially buffed most Ascendancy classes and have been introducing many powerful new items. The metagame has already shifted quite a lot due to these changes, so various more significant changes have had to take place elsewhere. PoE've called out a few in this article.

The balance changes mentioned in this article are not a conclusive list, they're just a bunch of important ones.

Zana doesn't have Breach this league
Ever since Path of Exile introduced the concept of different Zana levels adding league mods to maps, Path of Exile have been cycling the mods in and out. While Path of Exile occasionally run some back to back, Path of Exile often takes crazy ones away to let other ones have time in the spotlight.
PoE has decided not to run Breach as a Zana mod this league. It is still available from Sextants and always spawns naturally in 10% of maps. Also, it's similar to Abysses which now spawn on Sextants and also spawn in 10% of Maps (and can stack with Breaches). You will undoubtedly be able to play Breaches and Abysses, just not as reliable as the last league.
Speaking of Zana, the marathon to reach Zana Level 8 is shorter from 3.2.0 onwards, as quite a lot of Zana's quests now grant additional reputation for her when they completed.

Monster Rarity Damage Modifiers
This one is a little complex, but the TL;DR is that your mods like "monsters deal reduced damage" now actually work correctly in a lot more cases. Also, the monster damage is now scaled up more correctly by things like map mods, and monsters are slightly more dangerous now in situations where they were intended to be.
The full explanation:
In Path of Exile, there are many things related to the rarity of monsters (Magic, Rare, Unique) that increase the damage of those monsters. For example, a map mod might increase a boss's damage. Also, the rarity of a beast itself adds an intentional bonus to its Damage (which is why rare monsters do more Damage than magic, and unique monsters do more damage than Rare). Historically, these damage bonuses were always intended to be multiplicative (so that they had a decent effect) but implemented as the additive.
The most obvious way that this affects players is the "monsters deal reduced damage" mods or skills.
For example, If a monster skill has +200% damage (so it's dealing 300% of base), and you reduce monster damage by 10%. Then it would reduce the monster's bonus to +190%, rather than the +170% that would be correct (cutting 10% of 300% total damage).
The additive rules also diluted the impact and intentional difficulty that was meant to come from a boss having a damage aura stacking with its boss damage bonus. When stacked additively, it's harder to feel the additional damage.
In 3.2.0, these bonuses are multiplicative. Path of Exile has done a full balance pass of reducing damage in various places to compensate for unintentional increases in danger that have come from this change. Path of Exile wants to stress that it is intentional that stacked damage mods work correctly.
So there are some places where monsters are more dangerous.
We can't quickly make a list of what does more damage than before because it honestly depends so much on map mods and other situational bonuses. Overall, it's hard to notice and is unlikely to have a significant impact, but Path of Exile felt it best to pre-warn players and explain in detail what changed. PoE's happy to embrace making the game a little harder when fighting bosses, mainly because of the continued power creep over time.

Oni-Goroshi is a whole lot harder to find
People with Oni-Goroshi can level up very quickly. At its 3.1.0 spawn rate, a popular strategy is to farm the Twilight Strand for four hours to get the sword and then have an easier time with the playthrough.
We're happy with people doing this if they want, but it's going to take longer than four hours. PoE've both made it spawn a lot less often and also added a high degree of variance to it. It can generate at lower levels than before, but it can swing up a lot higher than before. It's a compelling item for leveling, so Path of Exile both wanted to make it less frequent and also for its spawning to be less predictable (like other unique items).
Oh, and have fun with the 3.2.0 Uber Hillock fight when you do find him ;-)

Bisco's Collar Nerf
The increased quantity of items from slain regular enemies has been reduced from 50-100% down to 35-50%.
That sounds like a huge nerf, but with the way that diminishing returns work for item quantity, it's not as bad as it seems.
Even after this change Bisco's Collar is still the best magic find amulet if you're taking advantage