When you say your Phals are getting too tall how many leaves are they carrying? Even my oldest Phal (20+ years) only carries 8-9 leaves and has never grown tall enough to do what it sounds like you're describing. I've cut off bare stem when repotting that no longer has leaves attached, but it sounds like you're cutting between still viable leaves. How large are the plants?
When you say your Phals are getting too tall how many leaves are they carrying?
I've attached a photo of one I'm going to divide next summer after it finishes flowering. This particular plant doesn't hold its bottom leaves well. I think I've divided it once before.