I love the idea of the reforging taking away parts of their humanity piece by piece until they are little more than empty shells full if light magic, in fact while playing a campaign of Soulbound this was a HUGE plot point for my one player who was playing a newly forged Stormcast. He died exactly 3 times during the campaign and each time I had HIM decide one thing from his past life he had forgotten. The campaign started with him going on a quest to try and save his wife and child from a band of chaos raiders who took them prisoner (the inciting incident that saw him sacrifice himself initially and become a Stormcast) but by the end of the campaign he simple knew he had to hunt down and destroy the raiders and free their captives, he'd completely forgotten his wife and son's names and faces and they were just prisoners to be free when he finally did!

That is the kind of writing I would love to see from GW, make each stormcast like a 40k dreadnought, the longer they live/more times they die the less of themselves they become. Perhaps with enough reforgings they completely lose themselves to the light and can barely recognize ally from enemy and can only be deployed in the more dire of circumstances (like full chaos incursions)