If iFlicks or subtler are able to take a MKV as input and output a MP4, it needs to demux the MKV anyway, but it does that probably on the fly, without writing the elementary streams on disc. It's good to know if I have to explain how to use the MKV files produced by BD3D2MK3D with an AppleTV, without having to demux everything. Thanks.
The updates are announced in this thread. (You can also see the number of the latest version in the title of the thread.)
You can also use the BD3DMK3D menu "Help -> Check for update" to verify if an update is available.
The same link is always used for the latest version of BD3D2MK3D:
BD3D2MK3D.7z. That link is present in the first post of this thread, and I repeat it in all posts announcing updates.
Only the (rare) beta versions are not available via the same link. If you want them, you have to visit this thread regularly.
I did a new little bug fix and I have implemented a workaround for problems in some (rare) subtitle files, and I will probably release v0.70 tomorrow...