It depends on your cabinets, but most modern cabinets don't need the extra rail. If you have solid wood panels then the extra rail is probably a good idea. However, in modern cabinet making solid wood panels are sort of a last resort, only used if you can't veneer wood onto mdf or use a plywood panel. Typically, solid wood is only used when you are staining a raised panel door. So if you are painting or you have a flat panel door, then you will likely not need the extra rail.

It’s personal preference but I think it adds some detail to tall cabinetry. I’d add it in unless I was going for a more modern look.

Agree with @bry911.

If not doing stacked cabinets, would not have "split" as it takes away from the clean, streamlined look of non-stacked cabinets.

I like it. :)

I have not seen this split look before in a kitchen cabinet. It looks nice❣️My cherry wood armoire has this split look.