When in "editor" mode (console command /editor) the adjusted vectors of inserters is not honored when placing them. For example, ticking the box long-handed drop in the overrides has no effect. Creating a custom pickup/drop location is also ignored. You can them after they are placed.
To be honest I don't know if this is something that changed recently, or if it has always been this way. I only noticed in the last week or so, but thought it worked before.