While attempting the Golden Needle challenge (1 hand per round, 6 discards, discards cost $1, ect.) I found that if you reduce your available hands per round to 0 (using the hieroglyph voucher for example or another method) the game would give you a hand at the start of each round to avoid an auto failure (which I assume is a cool intended safety net).
However when the needle boss blind came up, the game seemed to remove all of my 0 hands, and then give me both the safety net hand, and the “needle” hand.