Yes, I thought about the Vordenburg-Swedenborg similarity, too! Perhaps you could see it this way: I robbed (or shall I say "spared"?) readers of their Vordenburg experience, but included parts of the younger "In a Glass Darkly" that pertained to Swedenborg. Perhaps LeFanu did allude to him in form of the Baron and later decided to be more explicit by introducing Heselius, Swedenborg admirer and recipient of Laura's narrative.
PS: I was often tempted to fix some of LeFanu's more blatant literary shortcomings, like using the same adjective five times in a row, but that would have opened a can of worms I couldn't have measured up to.