Is there a way using Nraas mods to increase the pure breed pet chance value, like this mod https://modthesims.info/d/665011/no-mor ... rvice.html on MTS does?

This is a tuning mod, so the same resource can simply be modified using Retuner.
As noted in the description, it's the CASLogic XML - the Retuner path is probably Settings > General > By Tunable XML > Sims3.Gameplay.CAS > CASLogic > kPureBreedChance

thank you