I was about to say just that. Just because we have examples of high level technology, it doesn't mean that it's safely replicable without the requisite theory. I'd also favor the technologies that enhance our understanding of subspace, or gives us tools to better understand it.
I will note the mini core is fine. Even if it radiates, the worst that happens is we add more shielding and it'd still be massive size saving on the biggest ship component.
Also This:
I think we can't afford to delay the mini warp core, because its probably the sole component we have to give us a competitive advantage in a Lights conflict.
...and also smaller cores means much faster builds for gunboats