Refusing to support RAID (and disk encryption) is about keeping our distro images small and keeping what our all-volunteer team has to provide user support for simple. RAID is not "risky" but there are 20+ flavours of RAID and based on user requestts there isn't one thing we can add, so we end up being asked for many things and many tools and .. we have always tried to avoid "the death of a thousand cuts" where we keep adding little things that cumulatively lead to LE being yet another bloated general purpose Linux distro instead of the focussed and minimal Kodi client distro that we are (and always have been).
There are many distro choices that support Kodi so there's probably another with package management so you can add the RAID and other thingst you are interested in. You also have the option of taking our codebase and modifying it any way you like. That's the fab thing about open-source.