This isn’t the first time this has been tried, after my experiment I saw there were several posts on the subject. So for what it’s worth, here’s my experience:
The typical way to create a thick line is by using engrave. Here is another method, using multiple scores instead. In my example there is virtually no visible difference but the laser time is reduced by nearly 80%! In the the photo below are three 2" squares, each about .1" thick (ignore the two thin boxes). Inside each one is the method used, the settings, and the time it took to print.
To create the score, I divided the width of the desired line (.1) by the laser kerf (.008) & got about 12. I then created 11 copies of the original square, each .008 smaller than the previous (easy to do in illustrator using offset path). As you can see, the faster score was completed in about 2 mins while the engrave took about 9.5 mins. Below are closeups:
Although you can see the individual score lines in the closeup, they are invisible to the naked eye.
If you’re interested in this method, it’s worth a search, as I said others have investigated this already.