Bottom Watering & Rot

Is it bad to bottom water in a nursery pot (so that the soil is fully saturated) and then place that nursery pot into a decorative pot? Will is constrict the airflow and slow the plants drying time?

I did that with a terracotta pot. I put it into a bigger ceramic pot and the terracotta pot grew mold on it.

I also put a plastic nursery pot into a decorative pot, and the soil is taking forever to dry out and I’m worried about getting fungus gnats.