Would not recommend Dig Deeper. The author is a conspiracy theorist, not an expert.
RYF hardware with Libreboot and the Linux-Libre kernel will hurt your security, as this involves disabling microcode security updates (!!). microcode is a proprietary black box whether or not you update it. I’ve written about why FOSS != Secure before. Secure and insecure FOSS exists; Libreboot and the Linux-Libre kernel fall into the latter category.