So that's ~2lbs right?
I don't think it's impossible.
could you post us some pictures of your 20 oz set upi just hit 20 z's in my first coco and vert. i had plenty of room for improvement to say the least. 2 lbs. is def. attainable, imo.
I've not done it but I know someone who got 39.5 ounces so over 2 of your American pounds lol off one 600 doing a scrog in nft with SSSDH
and when I told other people this they quoted me other folk getting even bigger yields
To be honest in my experiance it's best to get that canaopy as even as possible try & utilize all the space that the light can over . My 600 covers a 1.2m square tent lovely. I am currently running my second scrog attempt this time with 5 plants , my previous was about 14-15 oz in coco . My current run looks a hell of a lot better than my previous . 1.5gpw is a verry good pull . It can be done with hydro & everything else dialled in I've seen many grows achieve this . But your talking chillers AC & everything else in the middle . I like coco I will be sticking with it for a few more grows . Experiance is everything in my eyes . Good luck on your venture man
Let's also not forget the small variable; how long a person veg's for.