Cats go nuts at the witching hour anyway, being inside or outside has nothing to do with it.

Basically, nah, they’re alright inside. They sleep for between 12 to 18 hours a day and get most active at dawn and dusk, so having some way for them to burn off energy with a good cat tree or the like will keep them occupied. And if they want more than that, they will come to you and make their demands known. And if that’s still not enough and you’re willing to put the effort in and do some acclimatising, you could get a second cat and they’ll keep each other occupied.