Saw some of these show up in my suggestions and have been thinking about trying one. Glad to hear it works for you.
Found a food thermos online with four equal size containers inside. The containers match the height for 3ml vials if you skip the stainless liner bowl, and each has a gasketed lid that seals tight. Thirty seven vials fit in one without shifting, so four containers hold one hundred forty eight total. Filled one tray plus part of a second and used a paper towel to take up the empty space until the next batch arrives. The thermos is stainless double walled with a leakproof lid and came with a shoulder strap that is not needed for freezer storage. Just wanted to share this with the group.