Doing a pattern for the cut will surely going to kill your system. Can you rather export it as DXF/DWg and use DraftSight to do the pattern.
If that is not possible, then create a part by extruding the profile. Now add another sketch below it and extrude that in different direction which will make the part a single body. Finally insert the part into a new assembly and do part pattern.
Did you try using the Geometry Pattern option? That helps sometimes.
You could also try creating a multibody solid of the scroll, patterning, and then doing a Combine > Subtract operation.
My first thought was "Have you run that by your laser operator?".
Do you even need to pattern it yourself? Or can the laser programmer take care of that. Send them a .dxf and ask them.
My other concern is the fact that it is all (everything I checked anyway) splines. The last time I was having parts laser cut splines got converted to a series of straight line segments. We either lived with the results or reworked the pattern to replace the splines with tangent arcs, very tedious. You may have a program that will convert splines to arcs, but we never found one that worked and was affordable. I would also venture a guess that the splines account for the file size and slowness.
Thanks everyone for your help, i passed the file onto my laser person, and we are working on a version that the customer is happy with. Customer wanted a totally random pattern, it has been a nightmare.
As they are finding out, wanting something does not mean it can be done.
Again, thanks for the suggestions.