Ive taken clones two or three weeks in and although they have taken longer to reveg and tweeked out a little throwing single leafs they came out fine. sometime you need to take a change to save the heirloom.
cloning is definitely cheaper. I've cloned on the day of harvest although it took forever to root. Other clones Ive done have been cut as late as 5 weeks.
dude they look fine. i've never cloned anything close to harvest day but i've done probably 5-6 weeks with no problems. just takes a little longer to reveg.