Font resizing when changing default font `:height`

Hi list,

Scenario: I defined a couple of faces with a relative `:height` property,
i.e., their sizes depend on the `:height` property of the `default` face,
which I set explicitly.

I use those faces to insert text in a buffer with `propertize`:

`(insert (propertize "Hello, World!" 'face 'my-custom-face))

Now, when I change the `:height` property of the `default` face during a
session, using `(set-face-attribute 'default nil :height <n>)`, I notice
that such string are not resized.

Similarly faces that are remapped don't seem to be resized.

However, text that has a `face` property as a result of fontification
*does* get resized.

Is this a correct assessment? And if so, is there a way to ensure that text
gets resized other than using fontification?

TIA

Joost


-- 
Joost Kremers
Life has its moments