There is nothing to suggest that any electric blue fish is a hybrid. There has also never been a documented case of Mikrogeophagus spawning with Andinoacara.
Please don’t post misinformation. Some of us strive to make sure there is accurate information, but uninformed claims make that difficult and are ultimately a detriment to the hobby.
To answer your other question, I would not add any more cichlids to this tank. Geophagus sp. Tajapos do best in groups which you don’t have room for, and jewels are aggressive (and African), so the cramped quarters would likely cause problems.