Is there a way to adjust the obo parsing strictness?

I wonder if it is possible to successfully parse a obo file that is 'slightly off'.
E.g. UO in its [current version is missing some dbxrefs](https://github.com/bio-ontology-research-group/unit-ontology/issues/44) which pronto, of course, does not like.
I haven't found a debug level setting on '_schema level_', but that would be helpful in ontology development, too, I suppose.