If he uses a new Intuition liner in his current boots, especially if he walks in them, he will have ~10 ski days of uncomfortable forefoot grip and mediocre heel grip. After those ~10 ski days the forefoot will pack out a little bit BUT the heel area will pack out faster and will be just as sloppy as the old liners by ~20 ski days.
IMO this is a much better application for Zipfit, but the cost of new Zipfit liners is like 80% of the cost of new boots.
If he can find pre-owned gently used Zipfits or if he can find cheap newish OEM liners he can keep the old shell plastic on life support - but buying new Intuition or new Zipfit really isn't economically justifiable here.
I have a friend who skis on a tight budget. She is lucky to have pretty “standard” feet. She hunts down newish OEM liners every year or two...she claims she can do this successfully and get a great fit for cheap.