If I only knew ... I also had that feeling before! But if a drive e.g. remembers a changed Booktype setting over reboots ... why not "learn" promising write strategies? I would say this is not sure, but possible.
On the other hand, I scanned the same disc with the "Smart test" in qscan and qscan said "not suited for 12x" - but the full test said "suited". If you get a batch of discs, maybe trying the full test, burning one disc, scanning it and if the results look ok to you, burn the rest at the same speed sounds logical to me. Maybe do a scan every 5 discs or so to be sure they do not change quality in your batch of DVDs.
I am not experienced right now to really be able to interpret the qscan results, anyway... so this is just what I assume!
Good luck and let us know