I know this question was discussed before. However, I could not find final resolution on this. Whether it was declared never implement or still open for discussion.
Base related popups (manufacture, research) are sometimes shown when not in base. One example is the battle summary when they report shortage of items and offer to manufacture them. However, manufacturing popup is for transporter home base where I don't keep my manufacture. It is in another one. I have to close the base, exit to geoscape, and then get to my manufacturing base and set production order there. I think it would make sense offering manufacturing at any base player like.