What is the criterion concerning the Taghut, such that whoever does not declare it to be Kufr becomes a Kafir himself, given the scholarly disagreement as to whether legislation without Allah is considered a Taghut that entails major disbelief, or lesser disbelief?

Allah Almighty commanded disbelief in the Taghut. Taghut is anything worshipped besides Allah. Scholars have mentioned several definitions of Taghut, including: anything by which a servant oversteps his bounds, whether it is worshipped, followed, or obeyed. It is derived from tughyan, which means exceeding limits, oppression, and transgression. Sheikh Muhammad ibn Abd al-Wahhab mentioned five types of Taghut: Satan, the tyrannical ruler, the one who consumes bribery, the one who is worshipped and accepts it, and the one who acts without knowledge. Legislating laws that permit the forbidden and forbid the permissible, and ruling by them, is major disbelief, and some scholars have reported a consensus on this.