Plumeria bloom on the tips, therefore every tip you remove is a lost chance to see flowers that year.
If you could post some pictures it would help, but here is what I would do.
In early spring (end of Feb, you will see them start waking up) cut back hard; and I mean, if you want to see blooms again at eye level, you want to go down to about 2 ft. Those sticks will branch again but you won't see blooms that year. But you will have a bunch of nice cuttings, which you can trim to your desired size. Plant those after callousing them for a week or two. You could even stick them straight in the ground among your other Plumeria. Since those still have tips you will likely see blooms on them that year.
Recommendation for the future: Plant more compact cultivars.
