The problem with him wanting to kill her as a child is that he went out of his way to create her through the Force just a few years prior. She hasn’t done anything to warrant being killed at that point - everything would be proceeding exactly as he intended. It makes sense he would start corrupting Ben and want her dead only after she disappears.

Technically all Snoke says about Rey in TFA is to have Kylo bring her to him. The fact that he wants Kylo to kill her in TLJ would still line up with the idea Palps was fully invested in Kylo at that point after witnessing she “has the spirit of a true Jedi”.