Inkscape - how to combine engraves to save time?

Good advice about the vector combinations. As for the rectangle, that’s tougher to get around but might be a candidate for something I posted a while back:

In this case I might try offsetting a bunch of paths by a very small amount to see what you get.

Alternatively there was some talk about breaking the shape apart to get it to stop scanning the whole area but I’m not sure where that ended up.

Also a discussion about engrave speed in general:

Let us know how it turns out!