It's an important stage to go through...
I Also collect RubRum seedlings, in Kitty-litter containers (or other large containers) and grow them up and out.. and sell them (cheap) as landscape trees. I've done this with young hemlock and thuja, as well. Under 1/2" in diameter, on public land in wisconsin.... you want it? it's yours.
The "Original Gangsters" of Bonsai presenting their feelings here ARE right about seedlings and especially oaks being a LONG... SLOW-GOING.. SLOW to "pay out" Process/processes... That may never see "refinement" within OUR lives..(Oak-Specific)
Buuut I'm gonna be spending my days taking care of a large amount of plants ANYWAYS.,. and I LOVE plants... I'll just alter my expectations of the seedlings and carry them AND my love of 'flora' with me on my journey.