My husband had to come off DAs after 10 years and change to Sinemet.
Initially he found it worked for about 2hours and then was immobile for about 2 hours until his next dose.
His wonderful neuro told him to take the doses half an hour earlier for 1 week and then decrease time between by a quarter of an hour per week until he was on continually.
This meant he took the tablets every 2 hours.
After working out the right time gap he then had to reduce the dose in each tablet by a very small amount until it became less effective.
Then he was on the right dose with the right gap in between. This trial and error approach takes time but does tailor the dosage to the individual.
Eventually he was prescribed dispersible Madopar in addition to the usual Sinemet to get him going in the morning and before and after his evening meal to overcome the protein problem. He can take one as a rescue also if he gets stuck.
Fortunately this regime has worked well for the past year.Hope this helps although it seems complicated!