Q.plumeria in a container
What would be the smallest size container to further the growth and flowering of my new leafing out plumeria?
The soil content and fertilization are probably more important than the actual container. Since they need good drainage, avoid planting your Plumeria in a pot that will force it to become rootbound at a very young age. Here are some tips that may help you: https://www.gardeningknowhow.com/ornamental/flowers/plumeria/growing-plumeria.htm