The second time I managed to squeeze in one side with a margin of ~6 threads. See bottom left.
I finally finished the outline and started the inner part only to realize that it didn't line up with the outline. See the upper right.
Sniping the outline is not an option because I'm running low on the floss, so I have to figure out where the error is and then unstitch. And I can't find the error.
The current plan is to stitch the inside and thereby find the error.
I knew there was a reason to start things in the middle.