Sometimes I have to connect multiple inputs of a spell piece to the same other spell piece, which can be achieved only by using connectors for a second connection. It would be useful if I could instead directly link the second piece to both of the first piece's inputs.

Unfortunately, Vazkii already stated that he isn't going to implement this.

This is not something that Vazkii feels to be thematical with the mod, however any addon developer is welcome to add this.