What is the * for here?

One thing I was thinking is that maybe not everyone wants to remove virtualbox (if they are using it for other things), so maybe it would be better to say here something like:

Optionally remove Virtualbox
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In some cases, if you still have virtualbox around, you can have various strange issues, if you do not use virtualbox for anything else, then it is advisable to remove it at this point. See https://github.com/pradels/vagrant-libvirt/issues/75 for more information about having two virtualization engines installed simultaneously.

and then still leave the known issues addition you added because it would be nice for people who get segfaults to find that