I've lost count as to how many breeders I have known over the years that fed NLS exclusively to their tropheus without any issues. IMO bloat is generally not caused from dietary issues (unless that diet is comprised of hard to digest fillers) but is usally caused by other stress factors, such as aggression during breeding, aggression over hierarchy/territory, low 02 levels, poor water quality, etc. Simply adding or subtracting fish can cause all hell to break loose in a tank full of trophs.
Below is a list of tropheus that a local breeder kept for several yrs, all fed NLS exclusively (including the fry) and not a single case of bloat, and most of those tropheus were wild caught specimens. He sold them a few yrs back to focus on Discus, which are also fed NLS pretty much exclusively.
Tropheus moorii Kambwimba Red Rainbow
Tropheus sp. Red Chimba
Tropheus moorii Ilangi
Tropheus moorii Bemba Orange Flame
Tropheus duboisi Maswa
Tropheus moorii Ikola Kaiser
Tropheus moorii Kiriza Kaiser II
Tropheus moorii Bulu Point Cherry Spots
My advice would be to introduce the NLS slowly for the first several days of feeding, for the same reason as one would for a dog. It allows the intestinal flora to adjust to the new food. After the first week of adjusting to their new diet feed somewhat sparingly a few times a day, NLS is a very nutrient dense food & a little goes a long ways.
HTH