We are testing it. I think that it is affordable for a LSP which deals with dozens of projects with AI files every month and has an Adobe license already (we have a , while it is not worth its value for a freelancer linguist, unless they work for a private sending AI regularly (and in that case they could even discuss with the customer because having the AI translated directly and not the translation in a Word file saves time to the end customer and reduces errors).

Indeed it is, but the options it provides for a professional dealing with AI files go way beyond anything a filetype is likely to provide.  So even if we had one it might be worth the investment.

However, the app is paid so it would be good to have it included as a native file type - considering we're already paying quite a bit for the Trados subscription itself ;) 

There an app available for this: https://appstore.rws.com/plugin/114/

The problem with the suggested conversion from AI to PSD is that you cannot go back to AI, so this is not an option when you need to deliver the translated files as AI.

Copyflow is what works better, but they discontinued it unfortunately so we are forced to use an old version of AI.