I expected to have the cookies, pinned tabs, etc. available at Orion+RC but didn't manage to get it to "sync" from Orion.
Tried
cp -r ~/Library/Application\ Support/Orion ~/Library/Application\ Support/Orion\ RC
as suggested at https://help.kagi.com/orion/misc/technical.html#syncing-settings-to-orion-rc-release-candidate but that didn't bring over anything. Cookies not loaded into RC neither.
I will stick to the normal Orion so far first.
There's a related post https://orionfeedback.org/d/4960-make-it-possible-to-importexport-orion-browser-data-to-another-orion-instance-like-rc-build