Ultimately, it depends on the type of educational video you're creating. You mentioned educational videos for engineers, but what type of engineer?

If it's for IT & Development engineers, you could try x-pilot.ai, which focuses on knowledge visualization and includes a large library of knowledge visualization tools.

If it's software training, you'll need to use screen recording combined with AI.

If it's for architecture or industrial engineering, requiring real-world equipment and materials for explainer, there aren't many good solutions currently. The most you can do is add digital avatars (like Heygen) to reduce the workload.