Hey now, I love my Top Bar Hive. I like the visibility of sloped sides to see what's going on inside and monitor it. I must qualify, I am a hobbyist, NOT a commercial op.
The TBH is a brood FACTORY. The bees crank out brood in that hive better than in any other. I have to keep an eye on it, but that's ok, it's at my house. When it's looking crowded, hey! make a split or take brood to strengthen another hive.
Here's how to bring brood into a Lang hive:
Sink two 1-1/4" drywall screws through a Lang frame top and into a selected TBH Bar (while the TBH is closed). The bees don't even know you've got a drill driver. Lift out the bar and Voila! It fits a Lang deep.
If your bees are calm, you can add the Lang frame's prenailed bottom & sides using a battery nailer to the top frame. Depending on your TBH's size, comb may need to have the bottom 1" trimmed with a kitchen knife.
I've never had comb collapse as long as there has been a few rounds of brood, since the cocoons make foundationless comb thick and rubbery. Honey is harvested from white-wax capped comb. No extractor, just a knife and some waxed paper to catch the drips.
But it doesn't transfer easily from Lang to TBH.
If you're going to have only one TBH, I suggest building a little TBH nuc to put a split into. Just to manage all the bees it cranks out.