Does reincarnation necessarily imply an improvement across the person's various different lives?
If yes, when you speak of "improvement", could you define what it is in this particular context?
One reincarnates until one is freed from attachment to maya
Some people are very attached to sex, so they will reincarnate to have lots of sex until they have had enough. Those who love sex will call this an improvement, but it could also mean you become a sex slave etc.
To become free from attachment to maya, starts by purifying one's senses, being a Master of the senses, meaning you don't think with your sex organs, but you use them for the purpose they are made for. Same for the other senses
On the other hand, when you are born you have forgotten all about past lives, you don't have vivid clear memory about it, with feelings etc. So, why to worry about future lives (reincarnation)? So, also no need to worry about improvement in this live, unless improvement in this life means being more happy in this life, then it makes sense to do your best to improve in this life.
Maybe it's best to follow your conscience. Your conscience will guide you step by step what best to do. No need to know about reincarnation.