I think you've been misled by the listicle-pop-history version of Hugo Boss's involvement with the Nazis. To quote from a previous answer of mine (How was the clothing industry (especially haute couture) affected by WWII both during and afterwards?):

Despite these noble intentions, the firms that stayed open and catered to the Nazis and collaborators generally tried to bury the fact that they did so, or rather, they just never talked about it. Hugo Boss had opened a ready-made menswear store in 1923, joined the Nazi Party in 1931, and started making, though not designing, uniforms on government contracts soon after, eventually using forced labor - as did, it has to be said, many other menswear/uniform manufacturers. Unlike the French companies, Boss suffered some legal penalties for his Nazi ties afterward, though he did get them ameliorated eventually. To say that either Dior or Boss "capitalized greatly" misses the context that they were not what they are today at the time: Dior was an employee of Lelong, and Hugo Boss-the-company didn't even get into men's suits until after Hugo died in 1948. Yes, they benefited and it's possible that their later success would not have been able to happen if they'd gotten out of the clothing industry for the duration of the war, but it didn't finance some kind of ultra-luxurious lifestyle for them at the time.

Hugo Boss did not actually design the SS uniforms - this is an assumption that's been made based on his firm's connection to Nazi uniforms and the brand's present-day reputation for being really sharp. His factory had been making cheap men's ready-to-wear in the 1920s, and he won contracts to produce uniforms (in part and in whole) that were, after 1940, produced with forced labor, and these contracts saved his business/family from bankruptcy. There was very little to set the firm off from any other German company led by loyal but non-military members of the Nazi Party.

On that more geeral note, you may be interested in the answer to Was the fact that companies like Kodak, Hugo Boss, Volkswagen ect were part of the Nazi war effort used against them by their competitors in the post war years? written by /u/kieslowskifan. This deals with what happened with German industries associated with the Nazis following WWII.