I think putting it into some better soil is worth the stress of upgrading the small pot. In the long run your tree should be much happier. I've had success with cactus soil and some perlite(1/4 ratio depending on the mix). looking for a 50/50 type mix for good water drainage.

I think the larger your plumeria gets the more stress that curve at the base is going to take and might just break? An expert might be able to train it back a little? You will definitely need a support stick in the new pot, so have it ready. Good luck :)

Take all of this with a grain of salt as I've only been raising plumerias for a little over a year.

Agree with wsb-man about getting some help training that curve. Know someone here who is an expert in this kind of thing and he'll be chiming in soon, just know it :)

As far as repotting- you would of course be stressing the plant, and I'd give some chances that the inflos might not survive. But the soil you have it in is obviously poor with sad drainage. I'd risk losing the inflos for getting the plant in some healthy soil. Everyone uses something different for soil, but the standard is 5:1:1. That's 5 parts pine bark fines, 1 part perlite, 1 part potting mix like Miracle Grow (not the Moisture Control). If I don't have pine bark fines I use Reptibark on Amazon, it's expensive but a good investment. (Your pot looks like the big bag would prob be best). Be sure your pot has good drainage...several good size drainage holes.

What are you fertilizing with?

Best wishes.

Nancy

I think the blooms will be just fine based upon the tree's perceived maturity...maybe delayed a bit but still should give you a good show. The large container should be a good fit for the plant. Although in a few years the plant may get a bit top heavy in a strong breeze. Good advice above about soil mixes. 5,1,1 or garden soil mixed with some perlite and bark fines will work just fine.

The best thing to do about straightening it will be to adjust it as best as you can when you up pot it and then let it take root which depending where you are may be a while before you can put any pressure on it. Then you can start to straighten it. It's probably going to be a very long haul effort. I think tape will not be strong enough. might have to use rope, twine, or wire with cut hose or foam padding. You will probably have to stake the twine outside the container in order to get enough traction on it.