MusicXML input parsing "feature"

Trying to isolate the source of a problem in the a MusicXML file, I wanted to use the

<?ignore … ?>

tag to comment out a large chunk of the file. In Dorico this produced the message

FATAL ERROR - internal error: Huge input lookup.

How big a chunk of data can you exclude that way?

Note, the error occurred excluding about 21 Mbytes of uncompressed MusicXML - this is a big project. But 21 Mb isn’t “big” for general file-handling. The complete uncompressed MusicXML file is about 230 Mb and working with that in a text editor is no problem!

I don’t know, is the short answer, and I would rather not devote the team’s time to finding out. The limitation could be in the libxml library we’re using for parsing XML files.