Cutting down, keep smaller buds on?

My father is getting ready to cut his girls down, and his friend told him to keep the smaller buds still on the stalk and cut higher than those, and in a few days to a week you will get about an oz off of those smaller ones..

Any truth to this? Any thoughts?

They will mature more, yes, if it's close to an ounce now, than maybe an ounce. The extra time and light helps them to finish maturing properly. Not a lot of weight is normally put on, though.

Are there any cons?

I like to cut mine in stages first I cut the big top colas first then after a couple of days I cut the middle buds then I let the popcorn buds on for up to two weeks then cut them they don't gain that much weight but u will definetly get more tthen just picking it all at
one time

I think this is also strain dependent...

I have grown a few varieties that mature bottom up, top down or all at once.

Cut based on Trichome color IMO.