Partying quantity range from other members

Me and a friend are having a discussion about how party quantity drop rate works in maps. To this day, players do still need to be around 1 screen distance to be able to increase the quantity/rarity of items dropped from who does the killing blow on the monster, correct? He is 100% certain party members can stay AFK at the start of the map and the quantity applied to the whole map, regardless if they're the player killing the monsters.

So this is how it should currently work:

"

Item drops from monsters are calculated based on the number of players nearby (13 metres - around six tiles, which is approximately a screen) rather than the number in the instance. The quantity of drops is based on the minimum of the number of players who were around at the start and end of the fight. This means that if you spawn a boss alone before bringing in friends to help (or if the friends leave during the fight) then it will only drop enough items for one person.

Actual quote from Chris Wilson in 2013 from this Patch Notes thread: https://www.pathofexile.com/forum/view-thread/274216

Thank you

Hi, have you found any more insight about this? We are also looking up into this with different opinions and information from several old sources.