In the end, I decided to follow Oldtool’s andvice and made two 1” wide x 3/4” thick hickory (pecan) battens per door. I’m leaving them installed until I get to the inlay work on the door fronts and start applying the finish.
I did order the T-track, and it seemed to flex more easily than the wood (and than a 3/4” square aluminum tube I have). I considered sliding a 1/8” x 1/2” steel bar inside the track to stiffen it, but I already had the world’s most expensive battens, so I stopped pursuing the idea.
So far the doors are still flat (within 1/16” or so), so I’m cautiously optimistic.
