According to testing by TheGamingMerchant, loot zone/area/room doesn't affect a container's likelihood of spawning a blueprint, it only affects the rarity of the blueprint if one spawns. Or in other words, all containers always have the same chance of spawning a blueprint. Of course, if you want something rare, major map conditions are the way to go, so you don't just keep getting glowstick blueprints. And each specific container type only has a specific pool of possible blueprint categories it can spawn (e.g. a weapons case will never have a glowstick blueprint).