Crazy hot hive! If the queen is making lots of bees, and they are very busy they will keep the SHB at bay. Swiffer sheets, flanel backed table cloths, and other foot tangling paper towels work placed on the tops of bars. The cd case traps, either with a bait checked regularly and emptied outside the hive or with legal appropriate baits should work as well. If they fit the between the bars beetle traps should work with them too.
You can also consider nematodes in your yard to kill them in the soil.
I think if you are seeing problems with them you need to take multiple prong attacks like with any other pest. These are general suggestions rather than Top bar specific. I assume there might be some kind of way to use the screened bottom board with the oil traps (Freeman) may or may not be appropriate to TBH and they are really effective if you can use them either with oil, soapy water, or DE.
SHB really suck, but I never had much trouble as long as the hive was busy and active.