Now it is. We've developed a phpBB Importer for Q2A.
As a proof we converted our http://www.impresspages.org/cms/answers/ from phpBB http://www.impresspages.org/cms/forum/
Now it's open source at GitHub - https://github.com/jankus/phpbb-importer
Welcome to the Q&A site for Question2Answer.
If you have a question about Q2A, please ask here, in English.
To report a bug, please create a new issue on Github or ask a question here with the bug tag.
If you just want to try Q2A, please use the demo site.
April 20, 2021: Q2A 1.8.6 released!