Hi there, Im pretty new so please correct me if im wrong! 
If I got it right, the lvl of a baby depends on the lvl of the parents (mean of parents' +1, +2, or +3 based on "luck"). As a pet with max lvl 41 or more cannot breed, this means that you can hit lvl 41 much before gen 10 (if you start from some high lvl parents).
A -1 pet scroll would allow us to fix that, and have lvl 41 pets at gen 10 (or less, depending on DNA which is totally random in my limited experience...). In other words, a -1 pet scroll can help a lot in making full stats pets at high gens without the risk to hit 41 before time. I think this does not limit the 'randomness' of the breeding process, as both DNA and number of breeds are (supposedly) random.
All the best and thanks for considering this
