The test project I provided yesterday has an overlay at the lower right corner actually, just like the actual full project. No difference in the content at all on the footage section. So I expect that same speed of the test project on the full project in the portion where it does the exact same things.
The test project took 18 secs only here, which is a huge difference with the full project's footage section.
I'm going to give 1 more try. This time by using the full project, but copying the footage and overlay to a new sequence, putting on the timeline's beginning and see how it goes.
It took 22 secs, close to the test project's speed. So there must be something wrong with the full project's sequence. 🙁 Something invisible that causes the slow down.