A changing program is an ill definition!
A program never change.
I found always over the years people speaking about a “changing program” something like a magic thing with the ability to improve itself .
How can a program change ? You can define how a program change using another program so we are speaking about U(yx) where y is a language and what really change is the program x the program in the language y is there something more than a universality ? No .
Every universal program has a parameter and if the parameter change its value we are watching an “automatic changing program”. The only thing you gain with an “automatic changing program” is to save the space of the code of the program that is a constant C so also space complexity never change .
So when someone is speaking about a changing program simply does not understand how the program change , does not understand which is the real program.
When you see a changing program remember you are watching the wrong program! You are watching a state variation.