When slicing remember to adjust the diameter of your mug to the size of your coaster. 2mm strength is sufficient. (Coaster in the pictures has 2mm strenght too - as a reference).
Colour change in the middle might look cool.
I used the Ironing feauture for the top surface finish. (Increases your print time)
Tip: use the grid in PrusaSlicer to estimate the diameter.
The author hasn't provided the model origin yet.