Hmmmmmm - - - - this email makes things at least somewhat more confusing.
If ALL contemporary CPUs have the vulnerability - - - then why the very vehement responses decrying the Intel J4115. Something like all procs have and/or still have hardware flaws at least mostly mitigated
by using Linux OS versions might have been more appropriate.
Re: Realtek NICs there have been a few people in the OpenWRT dev group that have spent a lot of time and effort working on getting OpenWRT working as a managed switch. See : Support for RTL838x based managed switches (not quite the way that I'd want to format that but that's a direct copy of the header).
Just for clarity - - - - does your aversion to Realtek NICs extend to suggesting that one not purchase a SBC that uses such for use with OpenWRT?
Thank you for your point re: SoC design.