This feature seems to be great for easy upgrading when you have previously installed packages manually! Especially when upgrading a device which is connected via wifi only.
I'll try it when updating from 23.05 to 23.05.1. I will Not use opkg list-installed though, since as @vgaetera already pointed out, I can see how this could possibly mess things up. Instead, I will just add my manually installed packages to the prefilled list.
I have some technical questions about this feature:
Does the prefilled list contain exactly the same packages than an uncustomized build? As in, if I would just leave it at default, would the resulting generated image be exactly the same as the precompiled one?
Will dependencies be installed automatically? E.g. if I had iperf3 installed manually on my install and want to upgrade OpenWrt, can I just add iperf3 to that list or do I have to add libiperf3 (dependency of iperf3) as well?