I'm sorry for making this discussion
The telomerase syringe restarts the mutation after it ends
Example: If you use the telomerase syringe on a person with the extra limbs, they will grow even more limbs.
In real life, telomerase is a enzyme that restores telomeres, the extremities of the chromosomes.
When the cells replicate, they lose a bit of DNA. That's why the telomeres exist, to protect the important part of the DNA. The cells will lose bits of the telomeres, unitl they end, causing the cell to start losing bits of important DNA, causing aging and other problems related to this.
The mutations on the mod involve multiplication, which implies lots of cell replication and lots of lost telomeres. Theoretically, restoring the telomeres via telomerase would allow the cells to replicate more times, causing the mutation to progress even further, leading to a even more mutated human, with, for example, super long arms and legs, lots of extra limbs, an extremely long body, etc.
Hope this will help people (I made this discussion because I can't comment lol)