No Export for You: Many Tenchi Muyo fans outside Japan don't view the entire series as a whole including the Doujinshi and Novels released by Kajishima-sensei. This causes them to miss out on important information, and the lack of this causes a severely ignorant case of Americans Hate Tingle.
The Other Darrin: Subverted in the 3rd OVA; Rebecca Forstadt had already replaced Ellen Gerstell as Mihoshi in Tenchi in Tokyo, as did Wendee Lee with Kiyone, who was previously voiced by Sherry Lynn (who continued her role of Sasami), Bob Papenbrook with Katsuhito and Nobuyuki, who were both previously voiced by Jay Hopper, and Mona Marshall had already replaced Petrea Buchard as Ryoko in GXP. Also played straight in the 3rd OVA with Mari Devon replacing Jennifer Darling as Lady Tokimi, although the latter did return to voice Ayeka. Michael McConnohie also replaced Jack Fletcher as D3.
In addition, all returning characters' voices were replaced with sound-alikes for their brief appearances in GXP. Of these replacements, only Mona Marshall as Ryoko became permanent, as the rest of the characters reverted back to their original voices for OVA 3. The only character voice to not be replaced is Rebecca Forstadt as Mihoshi, but even then, she was the SECOND Mihoshi. The original Mihoshi had retired years earlier.
Recent Doujinshi have been released that show Ryoko, Ayaka, Ryo-ohki, Mihoshi, and Noike's daughters and their relationships with Seina's 3 sons by Kiriko, Amane, and Ryoko Balta all of whom were born before Tenchi Muyo: War on Geminar. A picture of them can be found at http://postimg.org/image/qssdo16hn/