Yeah it makes sense to drop the distinction. With the last evisa update, it was announced you can apply from anywhere in the world but it is not the case with residency restrictions. Maybe in time places like China will drop the residency requirement. Japan did and is not overrun with DTV applicants despite record tourist numbers.
Malaysia is the most demanding embassy for DTV approval. I got mine in Taipei, it is not really difficult, they focus very much on showing business registration, prove of income - 6 months of statements with income deposits highlighted. No seasoning required. If you are ok with paperwork it is fine. You should check the main DTV FB group, loads of posts from Taipei applicants to get tips from. Indonesia, Vietnam are very good places to apply from.
Another conclusion, check the consulate you ae going to apply from. Xian is infamous for the failings outlined in the vid. Not all consulates in China are like that.
Yes a home office contract can count as remote work. Demonstrate your work online and submit permission to work remotely in Thailand. If applying in Germany they may accept a contract in German, you will need to confirm that with the embassy.