Arrow extract result ... Potential offset oddity (?)

[MvGulik]

Just something that looks a bit like a potential oddity to me.
(Note: I'm using an older 8.7.0 Nip2 build on Linux/Mint. In case it might matter.)

Using arrow extract to the pull the (inside) borders of a region I of course needed to do some offsetting.
Its one offset that strikes me as a bit odd. Kinda expected needing to use 1,0 or -1. But not 2 (?).

Related test work sheet:
Arrow_extrackt_test.ws.zip