* Copies of agency/school/institution/company documents must be signed by an authorized person and stamped with the agency/school/institution/company seal.
by the entity that provided the document. For example if you do a DTV visa by taking Muay Thai class. The paperwork regarding the school should be stamped by the Muay Thai school.
I haven't heard any stories yet confirming those extra documents in Taipei. Taipei and Jakarta are the most chill embassies at the moment. However, I would not take a risk by not bringing those documents. Vientiane also changed it overnight suddenly.