Help!? Final weeks. Revegging and foxtailing?

This growth is just your plant trying to have one last shot at being fertilized/pollinated before dying and is not caused by light leakage, just a survival tactic. I personally think your plant is ready to harvest and would start flushing sooner rather than later. No need to "panic chop", but your plant is on the verge of dying so leaving her too much longer will lead to degraded THC and give you flowers that will make you sleepy but not very high. This is because at this late stage, more THC is being broken down into CBD and CBN, which are 2 non psychoactive cannabinoids, than fresh THC is being produced. Personally, I harvest when there are about 95% brown pistils and do not judge my harvest timing entirely on trichome colour, which can have many unreliable indications, such as some plants never having amber trichomes or some strains that have 75% amber trichomes after only 4 weeks of flowering, due entirely to the genetics of those strains. Pistil condition relates directly to plant maturity and health and it is plant maturity and health that determines the chemical composition of trichomes and not trichome colour alone. Hope this helps,.......... Organoman.