The X-Y configuration you mention is an industry standard, and I love Rode mics. They’re very quiet for the money. I do understand what you mean about the set up times, if you’re feeling lazy. To stay with stereo rather than going down the mono / mixing path, I’ve been experimenting with a mid-side rig recently. My microphones of choice are the Sennheiser MKH40 / MKH-30 combo which is very easy to setup as it’s a coincident technique, and it captures the range of the flute beautifully.
I know some folks think the mid-side combo is some form of voodoo art, but it really is quite simple, once you get used to it. There are m-s mics that would work just as well in my opinion, such as the Audio Technica BP4029, and it gets away from the hassles associated with the X-Y configuration, you mention.