on the order you got the 1 inch, you will have no choice but to cut all the way through. If you have more room for a deeper cut, i would suggest going with a 2 inch, so you can cut to depth.
I would go with a thicker bit. The smallest i use is a .25 double blade straight cut.
you can push the bit all the way into the depth of the cutting area of the bit.
no more than 30 IPM - high rpms. go to your bits max
MAke sure that foam is held in place, if it shifts or gets pushed, thats all she wrote.
VACUUM VACUUM VACUUM! the foam will got freaking everywhere. It really likes to build up on the rails and increase the size of your wheels, and then next thing you know, your cutting in timbuckto. ,ake sure you get all those little flying pices of foam.
Run it raster, conventional cutting with a last pass. and i do a 1 inch ramp in.
LEt me know if you need any more help. If you have a .ai of what you want to cut ill turn it into a gcode for you. if you you only have easel.
Here is my last piece: