I wonder what is the optimal way for backing up .vmwarevm package made using Fusing with a virt. machine stored inside to import it from within VmWare Workstation or Player should this be necessary one day?
Currently we backup .vmwaresvm package generated by Fusion (virtual machine inside) to sparse bundle formatted inside to GPT and HFS+. This should ensure package container folder is backed up with all its internal items without any change. Maybe today or one day in future the package container format uses mac OS or latter's file system proprietary facilities. Those could get lost when backing up to non-Apple file system. Furthermore sparse-bundle images can be stored to mass storage formatted to one of lot of choices.
However if if one day it is necessary to recover virtual machines generated and backed up in the way as described above it will be hard to import them (or just .vmdk's) from within Workstation or VmWare Player which run under Windows.
Certain selection of utilities to read-access HFS+/APFS formatted volumes from Windows seem to exist (inclusively those commercial offers but for reasonable price). However opening sparse bundles can be hard.
In case of VirtualBox the situation is not that level of complication - mac OS package container format does not seem to be used. All is regular file zero containerization/packaging at file-system level.