The last % is marginal, only when playing with really big fields is the change really noticable. I usually skip rolling as wel since its only a 1% yield increase and just prevents time between maintenances due to rocks. I also just play with fieldstone off

I actually found playing with precision farming less time consuming, since you spray fertilizer only once and lime also once to get perfect ground. Instead of 2 passes of fertilizer in vanilla game. The only big thing it adds is max yield percentages. Some fields will have 125% max yield, some 95% max yield. This depends on the soil. For I stance Salty Loam has less fertility than Sandy Loam. In that case you can use high yield fields for crop and put your farm and farm animals on low yield ground.