Thanks for all the respones. I have 2 clones in 2" pots that are 13" tall and just drank a gallon of water in 2 days. There's a third straggler that finally started rooting. It's getting shaded pretty bad by them, but I'm not worried.

There seems to be a lot more room for the roots. I plan to take them to around 15-20". They seem pretty solid, but I may have to stabilize them down the road. If they do rip through the pots I'm hoping I can make something to grip the stem and maybe support it up higher.