It seems more like a ploy for Bad Dragon to monopolize on the fantasy dildo market via legally shutting down any competition.
This is probably what their goal is. I have never heard of "SinSaint" before and looking at their online store they don't appear to sell anything noteworthy so I have no idea why they are on BD's radar. None of the compare/contrast examples suggest a theft of design, just products that appear similar in a superficial manner because dildos based on canine creatres are going to have a knot. That just comes with the territory.
Someone earlier in the thread mentioned something like "hasn't BD been in hot water over stealing designs" and the answer is yes.
This old website that is unfortunately aging into obsolescence has some scattered documentation of alleged design thievery. It has not been updated in nearly a decade, though. As far as I can tell there isn't another website out there like this one that attempts to catalog all of their misdeeds.
I suspect BD is going to try and sweat SinSaint out because I doubt SinSaint has the coffers to deal with a protracted legal battle the way BD can. BD's parent company Bad Dragon Enterprises / Dragonfruit Ventures owns
a lot of shit. Most of it is obvious stuff from within the furry fandom like the aforementioned e621, F-List, and Furry Network (which was created because they made an unsuccessful attempt to buy FurAffinity at one point). There's also fringe things like
Input Output Flood (i/o Flood), a private server/VPN company based in Phoenix, AZ. Varka has his hands all over this company however if you look at the site's
About and
Staff pages he is suspiciously absent. He's also conveniently not listed as the company's founder.
Back in 2013 or so they also ran
Dragonfruit (Archive link), a company that aimed to serve a very specific type of artist: those who had been run off of or denied service on more conventional platforms because of the nature of their work. This is made clear by their mantra "Tired of other print shops telling you no? If it won’t get us thrown in jail, send it to us. We'll print it." Dragonfruit initially seemed to offer web hosting space and servers but phased this out rather quickly in favor of just operating as a print house for cub/zoo/etc artists. Dragonfruit wasn't sustainable though and closed up within a couple of years of operation. The umbrella company behind Bad Dragon is still named after this business, though. Another former asset of theirs was Herpy.net (Archive unavailable), a website that boasted a massive curated gallery of porn of reptilian characters and IRL pictures of reptile anatomy. Herpy predated the existence of Bad Dragon and its gallery, which received millions of hits, was pumped full of BD ads when the company launched and successfully kickstarted the business. Herpy was shuttered some time around 2016 when its poor reputation was getting to be too much of a potential liability for Bad Dragon. By that point it had long since served its purpose.
I know there are loads more shells/businesses owned by BD. It's just been nearly a decade since I last gave a shit about all of this and I've forgotten a lot of it. But yeah, they are fucking loaded.