Constant MAX_CONTENT_FRAME_BYTES 

pub const MAX_CONTENT_FRAME_BYTES: usize = _; // 393_216usize

The most raw bytes one piece of content carries, into a workspace’s store (ContentPutStep::Append) or out of it (ContentGetAnswer): hex doubles them, and the frame stays within MAX_REMOTE_ACTION_FRAME_BYTES. A caller splits anything larger.