That’s correct, all previous releases stay available on GitHub. However, if you have a need to download an older version, please do let me know why. In general, there should not be a need for this.
I did break compatibility in 1.9, by renaming “type” attribute to “class”, but there is a compatibility option you can set in your project (and likely I’ll undo this change in Tiled 1.10, because it keeps tripping people up). Then the maps should work in Carrion, unless there are also other changes that cause maps to not work.