Employment contract and employment certificate. Certificate being a document stating you are currently employed by the company and your duties or permission to work as a remote worker. Both items you mentioned aren't current documents.
if I may, to possibly smooth out the process for future applicants as well as embassy staff, provide photocopies of the 3 (or however many you have) certification documents to the registered applicants to include in their DTV paperwork submission to the embassies.
It's a 5 year multiple entry visa, you can enter and exit and re-enter whenever you like up to 180 days on any entry. Each time you enter you are stamped in for 180 days, you can stay 180 days or leave in 2 hours, up to you. You can do this 1000 times in the next 5 years.