Hi Evie! Congrats on your plumeria purchase, you will love it! The white bridal is supposed to have a fantastic fragrance!

Although yours is a Pudica and I only have the Rubra varieties, I do believe all plumeria love well draining soil. I put mine in regular Miracle Grow potting soil (not moisture control) and lots of perlite.

Personally, I would not put sand in there and I would not use moisture control anything (and I live in Texas!), especially since you're in Michigan - it may be fine for the warmest days of summer, but in the cooler days of spring, fall and winter it could be hard on the plumeria to sit in soil that retains more moisture than a regular medium. I know you said it worked for your other plants, this is just my opinion.

Plumeria do not like being cold and they don't like sitting in wet soil for very long, but other than that they are pretty hardy plants. Can't wait to hear about your progress, please keep us updated!

I have known a few "yuppers." Most of them go back to the UP sooner or later. Its a beautiful place in the summertime and downright brutal in the winter. That is pretty brave to try Plumerias in that climate.

If you want to keep it simple I would recommend Garden soil and perlite 1:1 ratio if those ingredients are available to you. If you want to go complex there is "gritty" or "5:1:1" which are reported to do very well in northern climates. Its your call to make. None of the three would be wrong choices for you. But I think most people on this forum will recommend you stay away from the moisture control soils for Plumerias. Good luck with it.

I would also recommend you get a heat mat and use it anytime the temps are below 60 to lengthen your growing season.