The key factor to growing taller is the chondrocyte hypertrophy. Larger cells means larger bone volume. Stem cells remain in the bone marrow post epiphyseal and diaphyseal fusion. These stem cells can differentiate into chondrocytes and if these chondrocytes undergo hypertrophy you will grow taller....Growing Tall Mechanisms - Mediplex

https://regenexx.com/blog/skeletal-stem-cells-found-living-in-the-growth-plates-may-one-day-make-us-taller/#gref

In an effort to attempt to identify and locate skeletal stem cells outside of the bone marrow, the new study used fluorescent markers to identify and track the behaviors of certain cells over time in the growth plates of mice. Prior to this study, it was thought that cells in the resting zone were inactive (at rest or even dying). However, they discovered active cells in the resting zone of the growth plates that not only rapidly divide and produce bone and cartilage cells but also play a part in the production of blood cells—all properties similar to bone marrow stem cells.

They also identified a tightly controlled feedback loop to control these stem cells during long bone growth. Basically, they are controlled by messages from both sides of the growth plate–one positive causing more growth and one negative arresting growth. This last finding could one day hold the clues to conquering problems like dwarfism and short stature. Meaning, we may see an injection or even a medication pump inserted one side of the growth plate to release chemical signals to trick the growth plate into producing more chondrocytes which will become bone.