No confusion but you perhaps created unnecessary fear in the faint of heart. If you still use an RTN66 or some of the other older ASUS routers, the April 2019 build is the last "release" but the beta is out and current to December 2019. With a few additions, it works and looks just like Asus-WRT or Merlin. If you haven't upgraded for a long time, you might still be able to upgrade to it from the Asus-WRT gui, but otherwise you will need the rescue disk or get to the Mini-CFE web server (I forgot how...you would need to get around the lock out on upgrades that haven't been blessed by the great uncle).
One especially nice "feature" is that you can easily back out of these and go back to your prior firmware if for any reason they are not to your liking. The main caveat is that there may be some regulatory issues, especially if you use higher than permitted power levels. As to safety or authenticity, it has got to be better than being exposed to the anonymous little guy in his bedroom who gets his sick kicks out of hacking into routers and doing bad things to the networks behind them. The unintended consequence of over-regulation of the routers by the FCC is forcing users to junk older hardware or risk being hacked.
DD-WRT or WRT may be able to support some older routers but figuring out which version to use and such is over my pay grade...the web pages are tortuous at best. Do I recommend John's forks? For the regulatory issues mentioned before, I can't ever do that. I also do not indulge in the silly practice of using higher power levels...if it doesn't receive well, more transmission power is not going to help a bit. More power=more heat=shorter lifespan=more CO2 if that worries you.
John's does install easily and the look and feel are not easily distinguishable for the final Merlin release for this model but the feature set is more complete. Of course, your call, but the Dec. 2019 beta seems just fine.