Personally I don't see a point in x86 for a Kodi client anymore. I migrated from an Asrock J4205 to a RPi 3 a year ago and more towards a client/server setup. I turned the J4205 into a NAS (OMV) running Tvheadend and everything else while the RPi "just" does the streaming to the TV through Kodi. Currently waiting for the drivers for the RPi 4 to get more mature to replace the RPi 3 with the 4.
Well if your just playing files off a server, I do not see a point to running libre elec. Just run jellyfin/plex/emby as there is no reason to buying extra hardware to stream local files
x86 is loads faster when using addons. just raw speed