I would expect them to remain in the custom configuration.
Recon777 wrote: ↑Sat Mar 09, 2019 12:40 pm Bob, is there any chance you'd be able to mod the Upgrade Planner so that it would preserve entity data such as custom inserters?
Here's what currently happens when you upgrade an inserter on Bob's Mods.
This is a pretty big deal because if you have an elaborate line with lots of inserters at custom angles, the use of an upgrade planner on them would be a huge mess.