Indeed, looking at the code seems it's already using it. I wonder what creates that delay though. I will have to investigate it a bit, probably by debugging BaseX, unless someone already knows. Could a SaxSource vs StreamSource be the issue? Or that doesn't affect performance? If my question is stupid, just ignore ;)
Thanks, George
Looks like it wants to use it [1]. You could try running below in the GUI:
Q{java:org.basex.util.Reflect}find("org.apache.xerces.jaxp.validation.XMLSchemaFactory")
/Andy