WDYT about:

On second thought, since this is just flushing /sitemap.xml .. does this have to be "Resource-Only"? Most ppl wont have Resource-Only flush agents setup by default. There shouldn't be anything under /sitemap.xml anyhow, so it doesnt seem like it would matter if it was hierarchical or resource-only?

It would be great if you didnt need a Resource-Only flusher since that tends to be the exception and not the rule.