BALANCE_TO_BORROW_THRESHOLD_WAD = 1.1e18. The same constant gates new borrows and withdrawals.
USD values use 9 decimal nano-USD. Token amount × Pyth price is rescaled by price exponent and mint decimals.
That bias is deliberate. The protocol would rather reject a tight borrow than mark an account safer than it is.
Lite receipts are included when the remaining-accounts scan finds them. Omitting a position from the scan fails the instruction — you cannot hide debt.