After flying the Alula with the battery's JST connectors I noticed quite a lot of sag when applying throttle. I measured the weight of the JST connectors (and wire) as 1g -- which was approximately the same as a pair of XT30 connectors. 

I also measured the contact resistance of the JST vs. XT30:

JST: 350mΩ

XT30: < 1mΩ

So I replaced the JST connectors on the ESC and Batteries with XT30. In order to balance the slightly heavier XT30 connectors I added some packing tape to the vertical stabilizer. This was a good thing since the tail was taking a beating when landing on any hard surface.

It turns out that the total added weight of the XT30 connectors is about 1.5g; less than 1% of the total Alula weight.

Performance Improvements:

I noticed that Amber stopped squawking about the battery voltage dropping below 7.5V when I applied the throttle. Flight times increased slightly, from 7 minutes to 7.5 minutes. Good enough.