Dermal tissue lip grafting - can it increase the height of the lips?

That’s a very insightful and well-thought-out question — and it’s great that you’re researching all your options carefully before proceeding.
Dermal tissue lip grafting, which uses your own tissue (usually from the dermis or fascia), can indeed enhance lip fullness and projection in a natural and permanent way. However, when it comes to increasing the vertical height of the lips, the results are generally more subtle than what you might achieve with a lip lift or other structural procedures.
This technique primarily adds volume and support within the lip itself, helping the lips appear fuller and slightly more elevated, but it typically cannot lengthen the lip height by 8–10 mm. That degree of change is quite significant and could alter lip dynamics, expression, and closure if attempted through grafting alone.
Multiple rounds of dermal grafting can sometimes provide incremental improvement, but there are limits to how much tissue can safely and naturally be added without compromising lip movement or causing stiffness.
In summary, dermal tissue grafting can improve projection and fullness, but its ability to increase vertical height is limited. If your goal is more about height than volume, a lip lift or a combined approach may be more effective, depending on your anatomy and goals.
Your approach to preserving your natural shape and avoiding overcorrection is absolutely the right mindset — subtle, balanced results tend to look most harmonious and age gracefully over time.