Depending on why it’s foxtailing, it could be leading to other troubles. If it’s too close to your light you could run into mold and burn issues. Too far away from your light and it will be airy or leggy, not dense. Some varieties are prone to foxtail, and others will late into maturity. I’ve seen them covered in trichomes and smoke good, they have also turned out to be a bust. It is just one of those trial and error things. A lot of other factors go into it.