I believe the same 🙂

The angle of the camera makes it difficult to gauge the middle lobe's length. If the middle lobe is the same length as the 2 side lobes it would be Passiflora affinis. If the middle lobe is longer than the 2 side lobes it would be Passiflora foetida var. lanuginosa/ Passiflora lanuginosa. We need to see leaves in their entirety. These leaves are curled and facing away from the camera, and shot at a bad angle, cutting off the middle lobe. Passiflora foetida is not native to Texas and is considered invasive in some areas. It has several varieties. The variety P. foetida var. lanuginosa seems to be the variety found in the Texas hill country. The leaves should have a strong aroma when bruised. Any variety of P. foetida would have a strong smell. It's common name is Stinking Passionflower. Passiflora affinis, (Bracted Passionflower) is native.

^ But, what if the middle lobe is shorter than the wings?

Because I just found another similar one at a local park...also with a slightly-shorter middle lobe. Are these maybe just Passiflora lutea with longer lobes?

Passiflora lutea and Passiflora imcarnata are the only species in the Dallas area. Their leaf lobe lengths can be variable, but if you look at photos of both, Passifora lutea leaf lobes are always rounded, and Passiflora incarnata leaf lobes always end in a sharp point, so this vine is Passiflora incarnata.

OK, here's some updated photos of it. It also develops some white splotches down its main veins and is definitely not Maypop...so what is it?

Passiflora lutea and Passiflora affinis both get those splotches? There aren't any keys to ID them using leaves and stems. The only way to know for sure is to go see it when it's in bloom. Affinis and lutea have very variable leaves can be confusing.

Passiflora lutea with bizarre leaves.

Wow, that poor tree looks like its been stripped at the base by mice or something.