I don't know anything about TC Maxi balls or black powder, but shot placement isn't different as a result. You are either shooting for the chest vitals, head vitals, or neck vitals, usually, so lungs/heart/upper thoracic spine, brain/brain stem, or cervical spine. You could be a liver shooter and enjoy tracking wounded game. Those are pretty much your shots. Pick any one you want.
Given that you are shooting black powder and your reloads will be slow, I would suggest CNS shots if you can actually make them (brain, brain stem, cervical spine, or upper thoracic spine. The hog will go down and be anchored, if not dead and it should be dead.
If your shot does not do significant CNS damage, either directly (which you may be able to control) or indirectly (which you won't be able to control), then you should expect the hog to run when shot and how far it runs will depend on how well it is shot and what is damaged. A double lung or heart shot may get you 0-100 yards yards. A single lung shot and the hog may run over 400 yards before collapsing. A liver shot can be another long track depending on how well it was shot.
If you are in open field, ideally nicely grazed, runners won't be a problem. If you are near the woods or in the woods, runners will likely mean a search of the woods, thickets, briars, brambles brush piles, or anything a wounded hog can hide under and then die.
Good luck and have fun!