If the target key is not a prime number, you could find a divisor for it, it could either be an even number or an odd number, I guess nobody has ever tried it yet.😉
I'd imagine finding the correct divisor is as difficult as solving the DLP, maybe solving DLP is exactly finding the correct divisor, I wouldn't know, because I never finished high school.🤣
Finally you reached the root problem or in other words security behind secp256k1. Figuring out Odd vs Even is literally the DLP itself. By far, any form of calculation on the curve won't work due to clock math nature of rounding around the resulting points.