So taking a simple RDF-Star triple with subject being a triple:
<< <http://example.org/resource/A> <http://example.org/property/partof> <http://example.org/resource/B> >> <http://example.org/property/p> <http://example.org/resource/D> .
and trying to convert it to-jelly with
jelly-cli rdf to-jelly ./in_001.ttl --to ./out.jelly --opt.generalized-statements=false --opt.rdf-star=true --opt.max-name-table-size=8 --opt.max-prefix-table-size=0 --opt.max-datatype-table-size=2
gives no error, but running jelly-cli rdf validate ./out.jelly
gives

So taking a simple RDF-Star triple with subject being a triple:
and trying to convert it to-jelly with
jelly-cli rdf to-jelly ./in_001.ttl --to ./out.jelly --opt.generalized-statements=false --opt.rdf-star=true --opt.max-name-table-size=8 --opt.max-prefix-table-size=0 --opt.max-datatype-table-size=2gives no error, but running
jelly-cli rdf validate ./out.jellygives