I should have realized it before. The E drone on my smallpipes is only slightly longer than the tenor A drone. This means that with a spare reed for said A drone, I can get that E drone to become a G drone. Why would I want to do this? For my D chanter, of course. This allows me to play [A,,A,] and [G,D] on my drones successively, meaning I can quickly alternate between playing tunes in A & D on my A chanter, and in D & G on my D chanter, and still have always two drones running.

This opens up a while lot of possibilities for me with playing smallpipes with the fiddle club. For example, during this summer's performances, we're playing three smallpipable tunes: a Cape Breton march in A (I can't remember the name off the top of my head), and Skye Boat Song and Road to the Isles in G. With a quick change of chanters and the uncorking and corking of two drones, I'll be able to play all three of these tunes. I might even work up a smallpipable setting of Flowers of Edinburgh, since we play that as well.

Drone configurations for A chanter:
[A,,A,] - for all tunes in A (all modes), D major, and Bminor
[A,,E,A,] - for all tunes in A & maybe E dorian
[A,,A,D] - for tunes in D major, Bminor, maybe A mix
[A,,E,A,D] - for alternating tunes in A, Bm, & D, though there's some dissonance

Drone configurations for D chanter:
[G,] - for all tunes in G major & E minor
[D] - for all tunes in G major and D major & mixolydian
[G,D] - for all tunes in G major and D major & mixolydian
[A,,A,D] - for all tunes in D major & mixolydian

I expect the smallpipes will get their public debut during the Virginia Scottish Games in late July.