Here is a 3D Relief engraving workflow on acrylic. 

This is the same file we used on the wood 3d relief engraving:

3D Relief Engraving On Natural Wood

The acrylic is 6"x 6" x0.75" cast. Thunder Nova 35-80, stock 2" lens, standard focus (6mm from nozzle to surface). The LightBurn File Is Attached at the bottom of this article.

The estimated time is 12:25. This laser config is correct in the estimation settings.

The actual run time was 12 minutes and 5 seconds from beep to beep.