Levain not ready
I am new to this forum and sourdough and bread baking in general. I revived a dried starter from a friend earlier this month and made my first loaf. It was dense and didn't rise much but I think that was more on account of the process I used and the lack of experience I had.
My second attempt was excellent. A recipient of one loaf described it as the best she's ever tasted. I got too ambitious and made a 3rd batch with fillings that tasted good but got very little rise.
I decided the culprit was my starter, which has been a bit more sluggish than usual. It bubbles but does not rise much. It was also a bit too runny for my taste at 100% hydration so I decided to reduce the hydration over a few feedings. I also feed with KAF Sir Galahad after running out of white whole wheat from Trader Joe's. Recently my starter seemed improved so I built a levain this morning following this recipe, which I used for my successful second batch: https://www.theperfectloaf.com/beginners-sourdough-bread/
I built my levain at 9:15 and began autolyse at 1:30. My understanding is that the upper limit for autolyse with mixed whole wheat and white flour should be about 3 hours. However, I am now concerned my levain won't be ready by then, or possibly at all. It has bubbles but has not risen considerably at all.
What do I do if my levain still isn't good by the time autolyse ends? Should I use it nonetheless and simply do a longer bulk fermentation? For reference, I'm in NYC and temp range where my levain is stored is around 75 F.