High Sierra’s APFS was optimized for Flash/SSD storage.
Running macOS in a virtual machine is commonly done for testing, development, and archival access. VMDK images labeled "macOS High Sierra" are distributed online, but obtaining and using them raises legal and technical concerns. This paper summarizes those issues and offers safer, lawful approaches.
Though primarily for classic Mac OS (9, 10.4, etc.), both sites host community-made High Sierra VMDKs.
