I have found that the timings on up shifting from rootmakers is pretty important to get continued growth from the plant. When left too long in the trays they will stall out on us and not continue with growth spurts. We plant a lot of acorns but also do Chestnut, maples, locust, sycamore, coffeetree and more but they are all different. The biggest thing that I look for is when pulling the plant out there is just enough root development to hold the shape of the cell, but when shook or gently manipulated with your fingers it falls apart. That is the ideal time to shift. If you pull it out and no soil comes with it, you are too early, if you pull it out and the roots are so dense it takes a lot of effort to break apart then too late.
Generally after about 6 weeks is when I start pulling them out and checking. Good choice with RootMaker, they produce the beat seedlings for us by far! Hope this helps, good luck!