Hello fapopo, not a bad experiment, if it works well and good. We all try to work around with whatever limitations we have.
But from what I know, your indoor experiment, may help sustain the plant continue on growing leaves, but not enough energy to make the blooms. At times, depending on the nature of the plant, in this case a Plumeria, they do require stronger light intensity and matching sustained warm temps with some humidity to encourage better blooming.
Also depends what cultivar you have, some cultivars are more heat and light needy than others. They are after all tropical succulents.
In my area, I have learned to accept that they will sleep and rest during the winter months, so I just try to be patient and wait it out. I also chose the cultivar that is the most cold tolerant of them all, so they will have better chance of enduring our mild winter conditions even if I deliberately leave them outdoors at winter time.
