"Matching hides" is standard advice for BPs & other snakes.They're shy & they want to hide but tend to choose "safety & security" (ie. the hide they prefer) over the right temperature. If the hides are identical, he'll choose according to the correct temperature.
I would suggest losing the "skull" thing- snakes grow slowly but meals make them suddenly wider- they've been known to get stuck in the holes on such things & need some dangerous cutting (the skull apart) to rescue them- sometimes the snake gets hurt. You never want hides or any decor that have such holes- they're intended for tropical fish- they don't get stuck. You want something like this instead, so the snake can always get out. The skull also has too many openings for a snake to feel secure in anyway. He's using it out of desperation. Your snake is stressed- please fix that a.s.a.p.![]()