Is it permissible for me to follow the opinion of the shaykhs in my city regarding building upon the lesser number of rak'ahs (naqsan) when in intermittent doubt, and building upon the complete number (kamal) when in frequent doubt, despite my personal inclination that my doubt is baseless, or must I follow the other fatwa which states that the person suffering from obsessive doubts (al-muwaswis) and whoever feels the illusion of doubt should complete their prayer and owes nothing?

"Istinkah al-shakk" (habitual doubt) means that a person experiences doubt every day, even if only once. The ruling for such a person is to disregard the doubt, and there is no need for rectification (of the prayer). He should perform the prostration of forgetfulness (sujud al-sahw) after the salām. As for someone who experiences doubt one day and is free from it another day, he is not considered "mustankah" (habitually doubtful). His ruling is to rectify the prayer by building upon the minimum (most certain) part of what he is certain about and to perform what he doubted, and to perform the prostration of forgetfulness after the salām, which is recommended. This detailed explanation is according to the Maliki school of thought.