To accurately simulate your job, I would need to know if you wanted to print 300 prints without a stop, or for example, a page that is 17" wide and 33" long which would accommodate 32 4 x 6 prints.
Did you want the prints with a small space for cutting to separate, or butted together with no space?
You can turn on the guideline edges for cutting by clicking on EDGES on the lower part of the main screen.

Fred

This was my first try from an hour ago before I read your reply.
You can make any configuration and any size page before it cuts.
I was asking about the cutting room between prints.
Please have a look at the screen snap and make corrections and suggestions.

That shows 20 4 x 6s on a page.
You can add 20 more and make page 2, and 20 more and make page 3.... etc.
..... or we can make larger pages since you have roll paper.

Fred