I am trying to test out the mosaic creator. If I do not have a rotator then what do I set the rotation value to? Is it possible to rotate to the framing I want and then create the mosaic off of that? If I go to plate solve and the rotation is off, will it fail to plate solve the image?
IMO I think you should have a look for the mosaic feature in EKOS planning. I didn't try it yet, but I plan to use it for big structures. You don't need rotation if you have GEM, but if you have ALT AZ mount, then you need to rely on the stitching software capabilities to stitch rotated mosaic and make sure you have enough overlap to cover the rotation based on your focal length.
There are two ways to look at this.
Either plate solve to get the rotation in your setup and use that value in the mosaic tool. Or plan your mosaic with a rotation you like and attempt orientate your camera to that value checking it with the plate solver. Once close, you may create the mosaic jobs with the final true rotation value achieved as is the case in the first strategy.
If you do not have an equatorial mount, you will be limited by tracking field rotation.