Should I apply for my DTV Visa as a dependant or individually?

What is YOUR purpose of visit to Thailand.

1. keep being self employed

3. being dependent

Just look at this print screen and notice that work is only mentioned in the first option.

Where?

From the official guidance, spouse/dependent DTV and workcation DTV are separate categories. Remote work is explicitly mentioned under workcation, not under the dependent (or soft power) category, so for a clear basis to work remotely yourself it seems safer to apply individually under workcation rather than as a dependent. That is the theory, in real life, I doubt it would make a whole lot of different, as people have been working remotely on all kind of visa (including simple tourist visa) before. What Thai law enforcement actually cares about is people not working within Thailand or for Thai customers illegally - they usually could not care less about you doing things for a foreign entitiy. In short: Spouse way may use the same documents your husband already get approved with. But your own path would give you more peace of mind. Also, no factual indicator one way would work faster than the other.

Dependant could definitely be processed faster. Just make sure there is sponsorship letter, marriage certificate etc.

If you are planning to work remotely from Thailand apply for your own DTV based on workation