Patience is key yeah.

Don't take it out too hard on yourself. At least you have maples.... I might have germinated two out of the hundreds of seed I've tried during the last two years, not sure if they actually are maples, I hope they are. And this tree still has a lot of potential, it is still quite young.

I don't want to meddle, but perhaps consider planting it out into the garden so that it has more space to grow rampant.

You could place a nice slab of rock beneath it's roots to control it's growth and force it to grow side roots which would make it easier to remove in the coming years and, it can still be styled while in the ground.

Good luck with the tree, I see potential for it and hope that the below image inspires you.