Yes and it has gotten much better in recent releases. On the other hand switching to an other sparql impl takes about 2 weeks of work in evaluation and deployme

Yes and it has gotten much better in recent releases. On the other hand switching to an other sparql impl takes about 2 weeks of work in evaluation and deployment. We can currently switch to GraphDB or oracle sem net without further effort. Blazegraph stardog are easy to switch too. Others would require a bit more work.