You can start pinching the tips of those with 2 sets of true leaves. After pinching, wait for new growth before you subject the seedlings to more experimentation. That way you know they have bounced back.

I'm a strong advocate of experimentation. But what you can do with your seedlings depends on how much you care about losing some of them. I didn't, so I did a lot and lost a lot. You can braid the roots (very loosely, they die if too tight), cut the taproot (I waited until they were 5 months before I did this), slice two plants and tape them together (not until they are about 8 months), plant them on rocks or Barbie head (make sure the head is shaved, the hair tangles with the roots), plant them upside down or in the ground. Given your location, your options are limited only by your imagination.

You're going to have fun, Ria lol

Pagan

Sounds like you really experimeted. Barbie head, lol. I don't mind loosing some plants as i prefer to have some unique looking ones. Rhe ones you experimented with, how did they turn out, especially the one where you sliced 2 plants and taped them together. I have a really tall looking seedling that is begging to make a spiral caudex. Just haven't really thought out how to do it as yet.

lol We found the Barbie head in the yard of the house we were renting. I was repotting at the time so I figured, what the hell, in you go.

Here's the conjoined yearlings today:

I'm tempted to slice again. But they are pretty much stuck together now, especially under the soil.

Pagan

Hi Ria this takes a year or 3

Pagan If you ever transplant the twins, It would be interesting to see a pic of what it is doing underground

Katie really nice. I hope in time mine will get gnarly underground so I can raise it to look like yours.