It'll still be vulnerable to a degree then. Android itself will have patches, but the SoC won't because Lineage don't have source code for that, only the binary

It'll still be vulnerable to a degree then. Android itself will have patches, but the SoC won't because Lineage don't have source code for that, only the binary blobs. Don't get me wrong, Lineage is great, but fully secure it isn't.