It feels like you're asking this from a good place. You want to grow on dtube and help the community grow as well. In a perfect world that would mean making content specific to each platform so that you could provide custom value to both audiences. Like you said YT and DT aren't the same thing.

The problem is it's not a perfect world. It's very possible that you won't have enough time in a day to develop two different concepts for videos that are tailored for each platform and then shoot and edit said videos. Even if you are able to then it's very likely not sustainable for a long period of time unless your quality standards are lowered.

The question I think is important to answer is what is the role of a content creator? The obvious answer is to create content but I think it goes deeper. I think it's to provide as much value as possible. Not the most value to a certain platform. So if a video serves both audiences then post to both. If it doesn't serve one audience then you can make it exclusive.
I would also argue that means you should avoid lowering the content's quality. Quantity is important but ultimately you want to be able to do your best work every time.

The only issue with this is it's focused on helping you grow best not DT. I think the biggest problem on DTube is it needs more high quality exclusive content. Why go to a different unfamiliar platform just to go watch the same videos. But YT has a bigger user base that you could potentially pull from to grow DT so I think quitting YT is a bad idea.

After all that I have two potential solutions. First is set a time period where you focus on making exclusive content for each platform. That way you are able to reach this optimal outcome at least some of the time and then scale back to your current norm to avoid burn out.

Second is continue on your current path but come up with a series. Something both audiences would like. This would be episodic content that you could work on in your spare time after completing your usual video for the day. Create a back log of these episodes and then start releasing them exclusively to DTube. Promote the series on YouTube so that you are bringing in new people and growing the community while still growing on YouTube from your daily uploads there. I like this solution best if you're trying to satisfy both your growth and DTube's while still being realistic about the possibility of burn out. Hope this helps!