All I know is the neighbor who planted them with lantana in a driveway bed that gets summer annuals and fall/winter pansies said she had a tough time getting them out when it was time to plant in fall.
I have two plants that began in 3" pots and I put them under a black walnut tree in an area where deer browse.
One of the few plants that can tolerate both conditions.
The one in the most sun has spread to two feet wide probably because we've had adequate rain.
You can clip them back if they get too big but you better plan on having them there as permanent plantings, like short shrubs.
Nice contrast against green shrubs and you can always tuck a few annuals between them.
Potting soil is fine for them. They'll expand to the soil underneath and the potting soil keeps the crown of the plant from rotting.
Give it a year or so and then decide if they stay or go.

In middle Tennessee, these plants die back in the winter and come up in the spring--and they aren't particularly invasive. The funny thing is I've never bought this plant, but one day I picked up three small pieces from the sidewalk that had been broken off from a plant, brought them home, stuck them in the dirt, watered a few times, and they thrived! In other words, they're pretty indestructible!

You didn't mention what zone you're in, but I'm in 8 (or even 8B) here and my purple heart (I'm assuming you are referring to setcreasea) also dies back in the winter as the previous poster mentioned. It comes back reliably but I've had it for years and it pretty much stays right where I put it. I have planted it in several places. I've always heard the name "wandering jew" applied to a different plant....tradescantia zebrina.

Setcreasea is a great plant for the south. It is very tough and the foliage color does not fade in our intense sun. It will spread, but certainly not in an uncontrollable way. If you want it to stay in bounds, take a spade and cut back the clump each spring. That will suffice.

They are not, however, great in pots. They will definitely hog up all of the water, nutrients and space in a season, bullying other plants into death or pitiful submission. I once tried putting them into a one gallon nursery pot and then sinking that pot into a larger pot so that I could have that color and trailing effect from it. It wasn't happy in those conditions until it split the one gallon pot up the side. Haven't put it in a pot since.

LOL....tha't how I feel- death or pitiful submission haha

I potted one with a very small tall ornamental grass and both are going well! Some in the ground have been being munched on but I sprayed today. I'm just in love with the color! I'll be sure to keep an eye on them!