The amount of glue you use and how you spread it on will determine how big or small your cracks are. The thinner, more evenly you put it on, the smaller, more even your cracks will be.
The glue should be tacky-ish when you start painting over it. If the glue is too wet or you don’t use enough paint, the paint will mix with the glue. You want the paint to be on top of the glue. It may seem too thick the first time you do it. Just wait for it to dry.
It does not take long for the paint to start cracking. Once your thick layer has been applied on top of the glue, do not paint over it again because it is cracking.