I got my shipment from Lacis yesterday, containing the cone of size 20 Lizbeth thread. Looks like this will be plenty for several large projects:
However, I can't get started on the table runner just yet. As suspected, the midline of the runner is difficult to get right. My tatted sample (pictured above) curves inward in the middle instead of forming straight lines down each side. I have a few adjustments in mind, but will have to tat a subsection to see if it works. I hope to have that figured out by next week.