Interesting ... just returned from making my uppers and lowers both 35 for regatta this weekend ... roller furling here is saggy and this was an experiment to see if I can get some sag out by evening tension on lowers ... with above info that mast is more likely to stiffen and help sag with backstay ... nice.
Here is a very valuable tip that I learned from Alan Andrews_.with your upper and lowers now set to equal you will definitely find that you will have a stiffer mast, and more of your backstay load will be transferred to your headstay as a result.
As we also know, when you do pull on lot's of backstay, even with your lowers set equally, you will get some top mast bend that opens up (twists off ) your leech and effectively depowers your main. The trick that Alan Andrews showed me is that when you crank on the backstay, also ensure you apply more corresponding tension to the mainsheet to compensate for the leech you just twisted off (opened up) or in other words_power back up the main. Ideally Alan's philosophy is that reducing headstay sag is the most important things you can do to maximize your upwind VMG in stronger wind.
Obviously you can still play the trav. And Alan is a firm believer is very aggressive hiking with the puffs. Having sailed with Alan and also applying his same ideas to other similar boats I have found his method works very well in breeze.
Good luck and let us all know how your regatta works out (of course you will likely end up with light winds now - it never fails !) best of luck !