amk, I'm guessing you are going to use the deep as an addition to the brood nest? I don't want to offend you but you do know about pulling up 2 full brood frames then alternating foundationless between those. If you don't you risk having wonky comb built out in an all foundationless box. I've had that happen to me when I first started foundationless. Fortunately it was honey and I did crush and strain on that box. Anyway the bees will spend all of their resources on building the deep and will ignore the medium, I believe.
I'd suggest you add the super first, work on them pulling in honey. Monitor the brood nest so they don't swarm on you. Then later in May or June add your deep and alternate your foundationless with the bottom deep if you want to overwinter with 2 deeps. I don't know how your area of Texas does as far as preparing for winter. I see Pollen.com saying you may often have winter blooms. If your bees do ok in a single deep then you may not need to add a double deep.