We are working on a whitepaper that's specific to the Bitcoin application, written in a less academic style that explains our threat model etc.

Nothing too special - we dump all the UTXO's from a full node that we run, and then concatenate and gzip data about each address (balance and recent txns).

Yeah, the delay is because the dumping actually takes quite some time. It's not as easy as you'd think to quickly dump UTXO's from bitcoind. I'm sure we can reduce the delay, especially if we're able to fundraise, hire folks, etc.