What you propose doesn't seem wrong, but it's effort that I am not sure is necessary. It seems like you are jumping through hoops to synchronize testing on multiple platforms. What if you go ahead and publish a release and say that it's tested/verified only on NetBSD, and that testing on other platforms is appreciated or in progress, and then release 0.6.1 when other platforms are confirmed. The flaw in your logic seems to be that if you declare something a release then the rest of the world will import it to their repos, use it, etc. without thinking, so that therefore you can't. What you're doing with prerelease branches seems a bit like working around that from the other end. Alternatively, find a way to build and install ATF from the ATF repo on a netbsd system and use that instead, perhaps with MKATF=no and doing it on the side. I use this technique with upstream packages that are in pkgsrc, doing a build --prefix=/usr/pkg and overwriting the package. Not 100% clean, but easy for testing and very little work.
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