Why does Blink have a Lightning - onchain imbalance threshold?

Blink has implemented a threshold of 10 million sats of Lightning/on-chain imbalance in a 30-day rolling window to help keep fees low for small transactions with low monthly volume.

The imbalance between Lightning and on-chain transactions can impact the liquidity of Blink and result in increased costs. By setting this threshold, we can ensure that our network remains efficient and cost-effective for all users.