@SeedsRUsEtsy
I have read numerous estimates for first-time blooming for seedlings, and the average estimate is around 5 yr. I can only tell you of my limited experience in growing plumeria from seeds, since that experience is only a span of 3 1/2 yr.
The first seedling I had bloom was my Kathryn's Fuchsia Fantasy. She had inflo. at 14 mo., was in bloom at 15 mo., and grew seed-pods at 17 mo. Plumeria experts have all said that this is an exceptional plant. At 20 mo., I had my second seedling bloom, my DD's Delight. These were single plants from two different seed-pod parents.
As I said, my seedlings are only 3.5 yr. old and there are only six of them. Two of them are those two mentioned above and the other four all have Slaughter Pink as their seed-pod parent. Two of those four now have inflo., so they'll soon be in bloom. That's their first blooming. These four are all labeled "January, 2014", which is when they were germinated. When each of these four bloom (and the blooms should all be different), I will name them.
Beginning last summer, I have taken a lot of cuttings from those seedlings, and in doing so, I have greatly reduced the chances for blooming. I rooted around 24 seedling cuttings last summer/fall/winter, and one of those rooted seedling cuttings bloomed in April, 2017. I have sold 8 of those rooted cuttings this spring, so I have no way of knowing whether any of them have bloomed.
I have two varieties of seeds, one from my MM's Soft Pink and one from my MM's Compact Pinwheel. They are both priced at $5.00 per dozen seeds. I began to germinate 10 seeds from the Soft Pink, 5 days ago, and I have already gotten 7 that have germinated. It is best to have fresh seeds.
I will have more seeds from a Celadine and perhaps one other variety in a week or two.
MM's Soft Pink
MM's Compact Pinwheel