Omg, jeez, sorry, I am in fact using CoreELEC. Corrected it.
I understand that the addons available in coreelec are not the same as those from “vanilla” (I guess x86) kodi.
After some more digging today:
I found out that the retroarch addon is the way to go. It’s very easy that way to have a playable nintendo 64 emulator (although after testing for hours, I will not live with the still noticeable input lag (timing mario 64 jumps) and hence tend to go the x86-route by replacing my odroid n2+ with some sort of nuc 
)
I also found out that the emuelec addon is discontinued, emuelec only supports aarch64 these days and the last addon-release that would work is from ~2019 so it’s safe to say that the emuelec addon has been replaced by @spleen1981 (github page)
Hope this helps someone else. Maybe there is nothing to add, then feel free to close the topic