Check PdfWriter should really update doc trailer when saving. Now the new trailer is written but the doc still has the old one
PdfMemDocument: Check the DeviceStream is not empty before doing an incremental update/signing operation
PdfMemDocument: Prevent Save() operation after signing operation
PdfMemDocument: Evaluate release the device after all objects have been loaded (eg. after a full Save())
PdfParserObject: Evaluate release the device after loading
Review all page import functions to check correct working/improve the code (PdfPageCollection::AppendDocumentPages(), PdfPageCollection::InsertDocumentPageAt())
Add fail safe sign/update mechanism, meaning the stream gets trimmed to initial length if there's a crash. Not so easy, especially since we are now using STL streams and it's not easy to trim files without access to native handle and low level I/O operations
Option to unfold Unicode ligatures to separate codepoints during encoded -> utf8 conversion
Option to convert Unicode ligatures <-> separate codepoints when drawing strings/converting to encoded
PdfFontManager: Consider also statically caching the queries and filepaths. Maybe we could also weakly (weak shared pointer) cache metrics instead of fonts
PdfName: Evaluate unescape lazily, or offer a way to debug/inspect the unescaped sequence a posteriori