Some leaves show white patches or (fewer) holes. The main symptom to my eye are leaves that are tightly folded up along their main axes with both halves apparently glued together by some "foreign" substance. (One such folded leaf is depicted in the lower right part of the 1st image. An unfolded leaf is depicted in the 2nd image.)
I planted this Ipomoea relatively late in our season: it has grown fast but has no blooms (yet).
What (perhaps who) is this and how can I get rid the cause?
I wonder if you have leaf miners working to cause those tracks in the leaves. As they progress through their instars they spin silken threads which can fix leaves.
This is possibly one of the many "leafroller" phenomena. A moth visits your garden and lays eggs. The eggs hatch and produce caterpillars that begin to feed on the foliage (you may see some leaf tissue damage on the plant). As they get larger they spin web cocoons to protect themselves as they develop into the next stage. The web is attached to the leaf and results in rolling of the leaf.
Usually there are few leaves affected and simply pulling the leaf apart to expose the caterpillar results in him dropping to the ground and becoming vulnerable.
There is a leafroller specific to the Ipomoea (Sweet potato/Morning Glory) family, but it could be one of many species.
