Is it permissible to perform two Friday prayers on a single day with the intention of seeking knowledge and expanding religious understanding, especially given that the Imam for the second Friday prayer is rarely available?

We do not know what the questioner means by "ordinary Friday" and "second Friday." It is obligatory for anyone who is required to attend Friday prayer to pray only one Friday prayer. It is not permissible for him to pray the Friday prayer again on the same day, because an obligatory act is only required to be performed once, and it is not repeated except for a reason. If it is repeated without a reason, then that is an addition, and an addition to an act of worship is not legislated. If the questioner prefers to pray with a preacher from whom he benefits more, then let him pray with him and suffice himself with that.