Like the recommendation of including a soundtrack CD for the UOE BGC BD set, I'm just gonna throw it out there with this recommendation for the two BGC Sonorama audio dramas to be included and translated as either a bonus video feature on the BD (with a static image or minimal moving background visuals as the audio plays with subtitles at the bottom), or as a bonus CD with a booklet containing the script for people to read along.
These two audio dramas, ちょっとあぶナイトセイバーズ (One Little Dangerous Knight Saber) & とLOVEる♥ウォーズ! (To-love-ru Wars), aren't really that well known so I think it'd be great if some sort of rarely heard of BGC side stories were included in the set for some new exclusive content. While I personally own the two cassette tapes myself and have listened to them, it'd be cool for the other fans to finally be able to hear it as well as they have some good character focus on Nene in one story and the other contains an amusing and weird look on Genom's workings.
Only issue for this would probably fall onto a separate licensing goal and difficulty in obtaining it, since the two audio dramas were released under the Asahi Sonorama label which appears to be a division of the Asahi Shimbun Publishing company.