There’s an option in the retropie_setup script, I think in the experimental subfolder. I think you can install all addons since it installs a full Kodi installation. It could be slower than a separately installed OpenElec, since OpenElec is a bare-bones Kodi without much in the background (no complete Rasbian running) and is optimized to run exactly that, Kodi, but I’m not sure. Last time I tried that, it ran pretty smoothly but could have been a bit slower and laggier than a separate installation.
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