I want to use mergerfs on my LibreElec box. What I have found is a docker image https://hotio.dev/containers/mergerfs/. This does not support armv7. However using docker addon and a simple dockerfile derived from hotio it's simple to use docker approach documented by them
Docker
FROM alpine:latest
ENTRYPOINT ["mergerfs", "-f"]
RUN apk add --no-cache fuse
ARG VERSION
ADD "https://github.com/trapexit/mergerfs/releases/download/2.39.0/mergerfs-static-linux_armhf.tar.gz" "/tmp"
RUN tar xzf "/tmp/mergerfs-static-linux_armhf.tar.gz" -C "/" && \
rm -rf "/tmp/mergerfs-static-linux_armhf.tar.gz"