When running epubcheck on an epub with a large opf file (13k+ lines, 841k) it throws the following StackOverflowError. Unfortunately I can't share the epub since it isn't public content.

epubcheck-4.2.6$ java -jar epubcheck.jar foobar.epub 
Validating using EPUB version 3.2 rules.
java.lang.StackOverflowError
	at java.base/java.util.LinkedList.unlinkFirst(LinkedList.java:178)
	at java.base/java.util.LinkedList.poll(LinkedList.java:679)
	at com.adobe.epubcheck.opf.XRefChecker.checkReadingOrder(XRefChecker.java:538)
	at com.adobe.epubcheck.opf.XRefChecker.checkReadingOrder(XRefChecker.java:599)
	at com.adobe.epubcheck.opf.XRefChecker.checkReadingOrder(XRefChecker.java:599)

I've seen that the recommended fix is to increase xss, but is there a way to change epubcheck to not require as much stack size?

This particular opf file has 6000+ <itemref> elements in the <spine>, and if I'm reading correctly it looks like these are evaluated using a recursive algorithm.

Question: Would changing the above to use iteration instead of recursion potentially decrease the required stack size?