I don’t know about carboplatin but PN from Taxol can continue to develop after treatment ends. Not always. Not necessarily to an extreme degree. But not certain. Most side effects do sort themselves out after treatment but not all. I had about six weeks of quite intense discomfort in my feet (heaven help anyone who stood on my feet in the tram!) but this discontinued. Nevertheless nearly seven years later I have very odd sensations in my feet (reduced feeling in some parts, heightened sensitivity in others). My oncologist was keen for me to stick it out but preferences vary and also change over time. Certainly in my case 85% of the recommended treatments (12) was considered as effective as the full dose (as far as anyone can tell). Always ask for a reason. Best wishes.