I like to call them, FS (flowering size), NFS (near flowering size), and with Mexican Pinguicula, that is a fairly accurate description, but still depends a great deal on the ability of the customer to understand and follow growing instructions, or develop growing skills. I do like the NFS plants to be well enough along that many will still reach FS despite many environmental shortcomings they may experience in their new home. In other words, they have the resources to reach FS, in desperation, especially if their new environment isn't optimal enough to help them to easily reach it.
I have learned to grow Mexician Pinguicula from seed or leaf-pullings to FS plants in six months or less (usually much less). But in my earlier days, with lesser cultivation experience and skill, I had seedlings sit there for several years, barely growing larger, at all. These days I can help my plants mature quickly, or let them grow more slowly (my choice), with virtually no harm to the plants. Drosera, Dionaea, Sarracenia, and many others can also be moderated in this way, with cultivation experience and technique.
I like having the experience of TC, but the know-how to propagate many plants, efficiently without the need for TC.
But I don't think a lifetime of experience with propagating plants is essential to understand this. Just a good book, website, or someone willing to explain some of the possibilities. The details, however, only seem to come with practice and experience.
Perhaps some growers have trouble explaining these issues. I know that for most of my earlier years of growing, I would have had trouble doing so.