For fmx::BinaryData you got nice functions to add data to a new container in chunks.
Reading a container is difficult.
* for normal containers we need to call functions like BinaryData::GetData to get data.
* for external containers we need to query paths, find one working and read file.
* for compressed containers we need to decompress on the fly.
As you probably have internal in FileMaker a function to do all those steps, it would be convenient to have a SDK function to read the data.
So a set of new function to open File, read in chunks and close. Does any file search, reading and decompression on fly.
This would make it possible for all plugin developers to easily support all types of containers.