The ruling on combining different types of طواف depends on which types are being combined. The most common scenario is combining طواف al-Ifadah (the واجب حج طواف performed after عرفات and مزدلفہ) with طواف al-Wada (the farewell طواف performed when leaving مکہ مکرمہ). Sheikh Ibn Baz ruled that if a حاجی delays طواف al-Ifadah until the time of their departure from مکہ مکرمہ and makes it their last act in the city, this single طواف suffices for both طواف al-Ifadah and طواف al-Wada. The key condition is that no additional activities requiring prolonged stay in مکہ مکرمہ should occur after this طواف.
Sheikh Ibn Uthaymeen confirmed this ruling and explained the principle behind it: the higher-ranking act of worship (طواف al-Ifadah, which is a pillar/rukn of حج) encompasses the lesser act (طواف al-Wada, which is wajib). This is similar to how one who enters the مسجد and performs the واجب نماز has also fulfilled the greeting نماز (tahiyyat al-masjid) by the stronger opinion.
Regarding طواف al-Qudum and طواف al-Ifadah, scholars generally hold that if a حاجی arrives in مکہ مکرمہ after عرفات and performs طواف al-Ifadah, it also covers طواف al-Qudum, since the time for the arrival طواف has passed. The Permanent Committee confirmed that these combinations are valid and reduce hardship on حجاج, especially in the intense حج schedule.