Ability to center subsequent nodes between 2 previous ones

[aejen]

I noticed that while if one node leads to 2, that (and previous) nodes are centered between the 2; however, if 2 nodes lead to 1, that (and subsequent) nodes are not centered, rather, they align to the left box. It would be nice if nodes with multiple arrows leading to them could be centered between the corresponding nodes.

df <- data.frame(from = as.character(c(1:3, 3, 4:7)), to = as.character(c(2:6, 6, 7:8)))
ggflowchart(df)