Minecraft wiki entry for Bastion_Remnant, associated text: Before Beta 1.16.0.59, some bastion remnant loot tables in Bedrock Edition contain entries for spectral arrows, despite them not existing in that version of the game.
This was likely not an error from copying the loot tables in Java Edition, as both editions had different loot at the time.
The structure bastion/hoglin_stable/starting_pieces/stairs_1_mirrored, despite containing the word "mirrored", it is not stored as mirrored like the other mirrored stairs. This has no effect on generation due to the placement of jigsaw blocks in the structure.
In Java Edition, before 1.16 pre-3, there were multiple unused structure files.
Two large stables were unused: bastion/hoglin_stable/large_stables/inner_4, and bastion/hoglin_stable/large_stables/outer_4.
Three sets of stairs were unused: bastion/hoglin_stable/stairs/stairs_0_mirrored, bastion/hoglin_stable/stairs/stairs_2, and bastion/hoglin_stable/stairs/stairs_3. They are removed as of 1.16 pre-release 3.
In Bedrock Edition, there are multiple unused structure files. Unlike the unused structures in Java Edition, these structures are more technical.
Two files named bastion/units/wall_units/edge_0, and bastion/treasure/ramparts/lava_basin contain blocks that have not been added to the game, including blackstone_bricks, blackstone_brick_stairs, cracked_blackstone_bricks, and chiseled_blackstone_bricks.
A test structure file, bastion/jigsaw_test, contains two oak signs, some jigsaw blocks, stained glass, and stone.
Buried sections can exist within the bastion and alongside it. Ore may generate alongside or within netherrack, but glowstone blobs can do so within its air.
Ghasts can spawn in the treasure room if the room is in the correct biome, leading to a surprise ramp up in difficulty.