Well they are still stuck with the fact that the plants were all created before God turned on the sun. So if each intervening space was 1/2 billion years, that is a long time to keep the plants out of the sunlight. You theoretically keep a plant in darkness for a few literal days, but beyond that you start running into problems.
God created the plants and vegetation on the third day. The sun didn't come out till the forth. If you have a consistent day/age theory, then that position is ludicrous. Now if God said he created all the vegetation 1/2 billion years before he turned on the sunlight, then I would believe him. But if we try to reconcile science and scripture by using a day/age theory, then we will take a most inconsistent position. The only way to reconcile it would be to have the forth day occur before the third. But why do we need to reconclie scripture to anything? We should be reconciling our thinking about everything else to scripture.
I'm not trying to reconcile anything. I'm just pointing out a difference between OEC and Theistic Evolution.
As always, for me the issue is what's on the page. The page says one thing, and then we begin the interpretive task. OEC is an interpretation, and I'm sure they would have some form of answer regarding the plants and the sun.
I know that scripture aligns with Truth, and that true knowledge (science)aligns with truth. Also, Jesus is The Truth. We might not yet understand how it aligns, but I am assured that it does.