...is it reasonable to assume that part of winter prep for a TBH would be to move the active bee frames to one end or the other?
It depends. I have side entrance holes at each end of the long box. This is an eccentric design based on my specific needs for a box which needs no bottom board, takes Lang migratory tops, entrances can be reduced or plugged totally with corks, and two colonies can be housed in the same box. Definitely not a statement re: entrances generally). From the end towards the center the most common pattern is pollen frames, broodnest, honey frames. The colony shrinks as winter approaches and generally they empty frames furthest from the entrance first and compress the honey in towards the broodnest. When I make my last check I can just pull out the empty frames and move the follower down.
Sometimes they move the broodnest about for reasons I can't discern, and end up with it furthest from the entrance. No problem. Just pull any empty frames out and push the rest towards the end with the follower behind.
Sometimes they split the difference and end up with honey frames on both sides of the broodnest. When I see this I move frames so that all of the honey is together. It doesn't matter what side of the broodnest it's on or where the broodnest is in the box, as long as the honey frames are grouped together, the bees will be able to move in the right direction.
If you build the top bars with a bee space between them and a cover that allows room for the bees to travel the top of the top bars. Like using lang frames in the hive. What do you think? waste of time?
This would remove the unique points of the TBH and leave only the disadvantage of comb adhesion. At that point you might as well build a long hive which would permit you to construct or use standard-dimension Lang frames and tops.
My long hive is horizontal, but takes foundationless Lang frames (w/ bee space between) and Lang migratory tops (bees can travel to the tops of the frames). I did this because I cannot lift so much weight but wanted a horizontal hive that would be as widely compatible with available standard equipment as possible, while requiring as little specialized woodworking as possible.
If you are interested in TBH for the smaller number and greater simplicity of components and building your own equipment cheaply from scratch, I cannot think why you would want to have bee space gaps (rather than bars of sufficient width) or space above the bars (an artifact of the need to retain bee space between stacked Lang boxes) for their own sake.