You're an excellent sport to this whole project.
What you wrote right now. Would say the first one could absolutely be used. The only sentence to make changes to would be to remove the ''-''->((Pounds of))<- firm teen tit meat grow upon her chest, ''
Would say the best cause of action is for you to just write and not feel like you have limitations. The transformations could have various length, making them short or longer depending on what you feel.
only thing to maybe keep in mind that these can be done s cutscenes with an illustration.
But the more various poses/locations she's in, the more art needs to be drawn.
(So say all her 1-5 stages happen on her desk then only 1 illustration is needed (with edits (no problem))
(If all 1-5 stages happen on either her desk or bed then 2 illustrations are needed and so on.)
But don't let that stop you, So gonna say just try it and then let's see if anything needs change in the workflow.