Robin,
To be honest some plumies are like petulant children and do what they want. I had a plumieria that did not bloom for almost 20yrs. Just like your plumie it was a super leggy, tall, single tip plant. The year I decided to throw it out it surprised me with an inflo, bloomed. The flowers were about 2", white and just ehhhhhh.
So basically you can try another location, with full sun, less water, SNG, new fertilizing regime, etc, etc., but a plumie will bloom when it wants to bloom. If you cut the plant now you may not get blooms for a while, but if your having height issues you may want to wait till next spring.

Good Luck

thank you. Now I don't feel so bad. I kinda like the element of surprise anyway. so glad I found this forum!

Since you asked what else you should be doing, if you haven't in 7 years I do suggest a root prune every couple of years / refresh the soil. It can kind of reinvigorate your plant sometimes. I know you said the pot is really heavy, but one of the gentlemen on this forum has a great method to root prune by taking a saw while the plant is in the pot, cutting a circle around how far in you want to prune, pulling the tree out and lopping a chunk off the bottom. Fill the bottom with some new soil, tree back in and new soil around the edges.

Also, being in Maryland, your growing season is probably a bit shorter - you may already be doing this but I would make sure the tree gets as much sun as possible during the growing season to make it happy too.

Good luck & please let us know how it goes!

Heheh, "petulant children" is a fine comparison. If they're getting out of hand, try more sun and root pruning as suggested. Sometimes strong threats help, too, LOL. There's also a school of thought that lightly pounding on the trunks with a soft bat (seriously, this is done with some fruit trees to increase production) can induce more flowering. I haven't tried it yet, but I will this spring. No, really. I mean it ;)

If nothing works, maybe it's time to get a more reliable blooming variety like Divine or Superround. These two also stay pretty small and dense so they might be a better choice for your zone, and they'll have a prettier shape when they're not blooming.

Jen,
"Pounding on the trunks with a soft bat"..lol Thats plumie abuse.....lol. There needs to be a dept of the government like P.P.S like C.P.S (Childrens Protective Services..lol).
With fruit trees maybe the pounding shakes pollen that falls onto other flowers stamens.

Robin,
I agree with root pruning if you have not repotted in a while, or if you want to keep the plumie in the same pot. I do drastic root pruning, usually cut off like 50% to 70% of the root ball off, then I will not have to think about root pruning again for couple of years. A lot of people do light pruning, like maybe 30% of the outer rootball.

Cheers