Tonight I gathered some reference/research material for this project. Fortunately, several others have done some really great work with this module, so here's credit to them:

1. LTC3780 Datasheet
2. Beyond Logic blog post
3. Templaro blog post
4. Great Scott video
5. Julien Lett first look video
6. Julien Lett adding a switch video
7. Julien Lett Solar Panel and SuperCapacitors video
8. Hansaka Perera's 1500w DIY Lab Power Supply
9. Almost full view of the top side of the WD2002SJ board

10. Chinese Datasheet
    1. Google Translate translation (actually quite good and helpful, especially regarding Schottky inclusion and setting voltage/current.
    2. Beyond Logic's English translation [PDF] 

The above links are not exhaustive - they only include information I found to be helpful in moving this project forward.

I have now read the datasheet a few times and am starting to process what my next steps are. The FCB input (pin 9) determines the operation mode of the chip. I intend to power up the board and set a few test output voltages while monitoring pin 9, in hopes of getting some practical result.

I also published a list of design goals in the description. Listed there is the intent to allow for easy operation mode switching - but for now I will be focusing on manipulating pin 9 for CV/CC, as I have a couple other projects that need CV/CC sources. I have some layout ideas in a notebook, along with other notes that might be added soon as well.