One thing about 2014.4 and plugins is that now when Sibelius delete bar 1, or a selection containing bar 1, it transfers any system text and blank page data to the bar that will occupy the same position that bar 1 used to occupy.
So, for example, Add Pickup Bar does not need to move the data when running in 2018.4.
I had to update a few plugins, such as Split Bar, Merge Bars, and Resize Bar, which handled this scenario, so that we did not end up with doubled system text. I updated Add Pickup Bar and Delete Leading Empty Bars as well, and plan to see if I messed any as people complain.
One thing to note: if you have a selection with the first bar selected and you call bar.Delete(), it WILL NOT restore the system data. However, if you select the bar with a system selection, and then delete the selection, it will restore it.