Hi! On a quick review of the deb packages offered at https://www.id.ee/en/article/install-id-software/ and the related source code https://github.com/open-eid and documentation https://open-eid.github.io/ I did not spot any reason why it could not be properly packaged for Debian officially.
If this RFP had more +1's I might do it. Are there enough Debian/Ubuntu users in Estonia to justify the effort?