The mod reduces the requirements for some of the challenges so you don't waste too much time on them.
Make a backup of your save and report issues if you find them.
Changes:
Bandit 6: Fence 3 horses instead of 5
Bandit 8: Fence 4 wagons instead of 7
Gambler 2: 3 wins instead of 5 wins
Gambler 8: 1 hand of 5 cards instead of 3 hands of 5 cards
Gambler 9: 2 consecutive wins instead of 3
Herbalist 3: Craft 4 items instead of 7
Herbalist 5: Craft 5 items instead of 9
Herbalist 6: Pick 5 different species instead of 15
Herbalist 7: Craft and use 1 special miracle tonic instead of 5
Herbalist 9: Pick 10 different species instead of picking all 43 species
Horsemanship 8: Kill 4 predators instead of 9
Master hunter 3: Track 4 different species instead of 10
Master hunter 6: Kill and skin 3 cougars instead of 5
Installation: put No_More_Grindy_Challenges in lml and you're good to go (thanks to WhyEm for the install.xml)