…or by running it on a SSD formatted HFS+ (which I believe is possible).
If the developer beta 8 installer is any indication while you may be able to
RUN High Sierra on an internal SSD formatted HFS+ you will not be able to
INSTALL High Sierra directly onto an internal HFS+ formatted SSD. (No HFS+ option was offered by that installer on my new MacBook Pro.) However, you should be able to install it on an external HD and clone that to the internal SSD formatted HFS+. You might have to forego the benefit of a Recovery Drive on the internal drive in that case. I am still unclear on how CCC handles that.
