I was looking at the D2000 documentation, first for the SoC alone and then for the Development Platform, and I wasn’t able to found anything related to the CR2450 available spot in the back of the board. However, checking the Schematic of the Development Platform (image that you can see below – page 10 of the document) there’s a spot for an extra battery that says BT1 EMPTY and it seems to be connected, now what I consider strange is that it says CR2054 instead of CR2450 as can be seen in the back of the board. Let us investigate this a little bit more.
Regarding the Product Brief, I took a look at the document and you’re right, at some point it says that there’s “19 input channels for ADC, 2.28MSps SAR ADC with selectable 6/8/10/12” and then in the table it mentions some more possible MSps data. However, given the nature of the document I believe it is just mentioning a possible configuration, not its only or final configuration. But I understand that it can be confusing.