You know, I thought the whole thing behind the 3D printed firearm community was about open-source sharing.
That is one of the founding ethos, However (and this is just my personal opinion which I think is a quite reasonable stance) I don't really see the issue with "silly" or "fun" designs like the BBG36 being closed source, because all it is a 9mm PCC in a mock up G36 Shell, which I don't believe really advances the cause of defeating gun control through the digital distribution of armaments especially when numerous other open source 9mm PCC designs exist.
Now in regards to Derwood Specifically it is complicated, the KC9/RTT9 is nothing special (the magnetic delay stuff simply does not work and what it does ie removing slop between the bolt and upper isn't really a game-changing feature and it only does so temporarily. But I have to admit I am biased against Derwood's closed source designs because he's just so pissy in his interactions.
Now for the real meat of this post
Suppressors, Business, The Military Industrial Complex and The Future
There will be a TLDR at the bottom
Yesterday TFB put out an article announcing the release of the Buck 30 Suppressor from Silencer Central, the Buck 30 is a Stainless Steel, Tubeless, 8 baffle, 6.9in long, 1.54in Diameter, .300 Win Mag rated suppressor with an MSRP of $699. Now what popped out the most to me in the article is who the Suppressor is being made in partnership with, none other than Buck Commander. What is Buck Commander? It is a subsidy of Duck Commander which was started by Phil Robertson (yes THAT Phil Robertson, Patriarch of the Robertson Family who most Americans know of from the now cancelled TV Show Duck Dynasty). Now why is this interesting? Because a company that mainly sells equipment that is targeted towards who many would consider to be Fudds is now somewhat involved in the big bad assassin tube market. I believe this could be indicative of the beginning of a larger cultural shift towards the mainstreaming of Suppressor ownership that coupled with extensive ASA Lobbying, Post Bruen Lawfare and popular demand could eventually result in Suppressors being deregulated or at least removed from the NFA and treated as traditional firearms, only requiring a Background check.
I also base this assumption on the somewhat recent mass adoption of Suppressors by the US Army and Marine Corps, The Sig HLX and KAC NT4 respectively, No longer will Suppressor usage be largely relegated to Special Forces, Now all Combat Arms members will get one. In some aspects Civilian gun culture is downstream of Military trends (and in some cases it is the complete opposite). Much like how the GWOT alongside the expiration of the 2004 AWB and Call of Duty 4: Modern Warfare propelled AR-15 pattern rifles to be America's most beloved Semi automatic rifle, I predict that a downstream effect of the mass adoption of Suppressors for use with the common Soldier or Marine will within 10-15 years result in a favorable cultural shift towards and increased demand for them
The Gun Industry as everyone also can guess has a massive financial incentive to push as hard as they can for suppressor deregulation. Lets look at the facts, Suppressors are not a complex good to manufacture, they have been manufactured since 1909/10, they are only as expensive as they are due to regulations and comparatively low demand. For example, Aero Precision recently put their Lahar 30 suppressors on sale for $300, while I am not an expert in industrial or product design I would wager to guess that after Material costs, Labor etc the construction costs for a Lahar 30 is somewhere in the range of $75-100 but would drop with deregulation, if the NFA were not an issue Aero could (again another assumption) pump out 100,000 a year, assuming an MSRP of $200 per suppressor that is $20M USD in sales.
TLDR: I believe the stars are beginning to align on Suppressor deregulation, I don't think it will necessarily happen soon, but I do believe it will happen and I would be surprised if it doesn't happen by 2040.
Also, 3D Printed belt fed Gatling Gun that uses AR barrels and modified bolt assemblies
Many more images are available in the reddit thread but I didn't want to clutter up this already massive post all that much more

The Designer, Nopel who is also working on a Roller Delayed belt fed 9mm called the RBC-9 which I believe uses an entirely DIY roller delay mechanism says that the design is 90-95% complete
In 15 years, if you disregard the law and are willing to pony up the money you will be able to 3D Print, ECM/EDM CNC and use DIY/COTS parts to make your own minigun for $7500, it may destroy itself much faster than one made by Dillon Aero, but that won't matter because you'll only ever be using it during your Killdozer 2.0 rage spree.