Minecraft Version: 1.12.2
Forge Version: 14.23.5.2838
BuildCraft Version: 7.99.24.6
log: https://pastebin.com/g80mX7nG

BC outputs a lot of logs about ghost loading at some positions. But these positions have nothing in BC and no player went to these chunks where the positions are before.
About 300MB logs are output in only a few hours and actually there is a high delay may be caused by this issue.

none of those positions have to be BC blocks, are there any BC blocks next to them (more specifically logistical stuff like wires and gates?) this is BC saying that it's loading a block in an unloaded chunk (usually because you have stuff on the edge of a chunk that needs to check the blocks around it for other things like redstone signals)

emmm there is no BC block in these chunks or the chunks around them. Wires and gates used which are most near to these positions are dozens of chunks away. I think these blocks have no reason to be loaded by BC but BC really ghost loads them too frequently.

In this context emitter specifically means a buildcraft pipe pluggable that is capable of emitting a pipe wire signal - which is basically just a gate at the moment (Specifically a pipe pluggable that implements buildcraft.api.transport.IWireEmitter).

If you no longer have any buildcraft pipes at those locations then it means the per-world wire registry has old data and should be deleted (saves/<save_name>/data/buildcraft_wire_systems.dat and saves/<save_name>/<dimension>/data/buildcraft_wire_systems.dat). Edit: if it's a server then remove saves/, but the rest of the path should be accurate)` Note that you must delete these files when the world isn't open!

Removing this file only makes unloaded wires not load up properly, so you'd need to visit all chunks with wires in to make it work properly again. There shouldn't be any other consequences from deleting those files.