The idea behind the timing advance is better throttle response and power, I've heard it'll help economy too, can;t verifty that..
Since you are burning wvo it would be more advantagous for you.. WVO burns a bit slower than diesel, injecting it slightly sooner gives it a bit more time to burn more completely getting the most out of it.. I've often thought it would be nice to have a way to advance and retard the timing on the fly ( other than the cold start) On wvo my car runs great a about 1.05mm but on diesel it's a bit too clattery for my liking...
I think I made some sense there, please correct me otherwise...