It's easy to change the shapes of beads that are made using a bead roller, and the challenge is to do that consistently. Make yourself a "squishing guide".
First, grab your favorite acrylic block that you use for making swirlies. Find 4, 6mm round beads or crystals. You are going to place these beads on your work surface to serve as "squish-stoppers". Place the 4 beads such that you can cover all of them with your acrylic block, which is the squisher. If desired, you can secure the 4 squish-stopper beads with a teeny spot of clay or double sided tape so they don't roll away.
Take a CLAY bead that you have rolled out in the tri-bead roller round bead slot, and put it in the center of the area created by the 4 squish-stopper beads. Then squish with the acrylic block. The four beads will make sure that you apply even squish from front to back and side to side so you won't have a sloped bead. If your acrylic block is big enough, you can do this with several beads at once. What I have described here will make rondelles.
Do the same thing with larger or smaller clay beads to begin with, and you can also use larger or smaller "squish-stoppers". Also try it with beads that come out of the oval bead shaped bead roller, and you'll get some nicely shaped pillow beads. The larger the clay bead you start with, the more it will spread when you squish. So you can make beads of different sizes and shapes, but they will all be the same thickness if you use the same size squish-stoppers.
In the photo:
The single round bead was made with the tri-bead roller. The one under the acrylic shows how it squishes. I make the hole AFTER squishing - these are already baked. The second bead under the acrylic started out as the oval bead from the tri-bead roller. My four stopper beads are 6mm round masking tape. held steady with tiny loops of
On the strand - a few beads that are still round, but everything else has been squished. If you look closely at the BOTTOM, you can see squished oval beads on edge at the far right end, and the ones that appear wider are face-up.
Sizes can be varied by starting with a larger clay bead, and still using the 6mm stopper. Or start with the same size clay beads and use a 4mm or 5mm bead as the stopper, in which case the beads will spread out a little more and be a little thinner.