Morphtarget + Clothing - Basic Question

I am sure this question was asked about 20 times already, but forgive me as i could not find what i needed …

In our project we do plan to allow character customization by using morphtargets. This includes stretching some parts like the player height, which ultimately will influence some other morphtargets like … leg height - and with it knee height and probably width as well.

If we now create pants for this character, the width and height (and depth) must be completely recalculated even before syncing additional morphtargets - correct? I can imagine how to do this, but is this the only way or did I miss any kind of shortcut for this workflow?