So I was reading the Armorer's 9th level feature and came across this text
In addition, the maximum number of items you can infuse at once increases by 2, but those extra items must be part of your Arcane Armor.
I didn't remember reading about a limit to the number of items you can infuse at one time so I went back to check the Infuse Item feature:
You can infuse more than one nonmagical object at the end of a long rest; the maximum number of objects appears in the Infused Items column of the Artificer table.
So is this saying that a 9th level armorer could have 5 items infused at a time as opposed to the normal 3, provided 3 of those infusions are on the distinct pieces of their armor?
Best Answer
A 9th level Armorer can have 3 infused items plus 2 additional infusions on their Arcane Armor, for a total of 5 infused items.
Consulting the Artificer class feature table, we see that a 9th level Artificer can have up to 3 items bearing infusions:
Then, the Armorer's 9th level feature Armor Modifications states:
This increases the total number of infused items to 5, but the two extra must be on separate pieces of your Arcane Armor.
So from 9th level onward, an Armorer can have two more infused items than the number shown in the class feature table, as long as at least two of their infusions are on Arcane Armor pieces.
So you're reading of the rules here is mostly correct. When you state in the question:
The only correction is that only 2 of the infusions must be on Arcane Armor pieces.