Hahaa. Same here for now. The first problem is the large number of files that need to be changed, especially when adding new body parts with descriptions. The second, that you can't really test it until EVERYTHING is changed.

I'm not sure this version works anymore - it's from more than 6 months ago.

Here's how to tinker with this however you want:

Go to YourStriveFolder/Files/Scripts and open up "variables.gd" - funny extension, but you can open it in notepad or anything like notepad.

Find the following paragraph(hint: ctrl-f "#Pregnancies"):

#Pregnancies
#warning-ignore:unused_class_variable
var pregduration = XXX
#warning-ignore:unused_class_variable
var growuptimechild = XXX
#warning-ignore:unused_class_variable
var growuptimeteen = XXX
#warning-ignore:unused_class_variable
var growuptimeadult = XXX
#warning-ignore:unused_class_variable
var traitinheritchance = XXX
#warning-ignore:unused_class_variable
var babynewtraitchance = XXX

Everywhere I have "XXX", there's a number - you can change those however you want. the duration and growuptime variables are measured in days. The inheritchance and newtraitchance are in percentages.

Then, just save the file and start Strive, and badabing badabang, you're good to go!