I wonder if it does make sense to do DIY conversion today?
Give us a few more words. What are you calling a conversion?
I mean do it from scratch - convert car by replacing combustion engine with electric motor.
If your goal is to build something as good as or better than what you can buy the answer is NO.
If you enjoy creating and building technically challenging high value projects for your own enjoyment the answer is YES.
From the aspect of the security, I think you will not to do it by yourself.