It's best to center-focus on the cutting or plant itself to keep the aesthetic value.
If a small plumeria cutting or plant is planted in too large a pot, it gets lost. If a large plumeria plant is placed in a small pot, the visual imbalance becomes the focal point. The combination appears out of balance to the eye.
The budding and rooting plumeria cutting in the following picture is 12 inches tall and has been planted in one 6 inch pot. The cutting is in balance with the size of the pot.
Small plumeria cuttings and plants which are planted in large containers seem to be lost and it can be potentially harmful to the root development of the cuttings or plants.
This is a more important issue than the aesthetic value. Planting plumeria cuttings and plants in larger than needed containers may result in their demise due to stem rot as too much moisture is available over a prolonged period of time.
The right proportional size pot or container per plumeria size allows for proper drying out of the planting medium compared to the moisture retention of extra planting medium of an oversized pot.
Plumeria gardeners looking for advice on this issue need to understand that there are regional differences that need to be taken into consideration.
For example, plumeria gardeners living in the tropics may suggest to plant plumeria cuttings and plants in large containers to allow for adequate root development.
This may be good advice in tropical climates, but it's not recommended that plumeria gardeners in temperate climates follow this advice. Temperate climates don't experience the same intensity of the sun, even temperatures and high humidity.
When choosing the right size container for your plumeria cuttings and plumeria plants make sure it is in balance with the size of the cuttings or plants.