While I'm here, I've skimmed the stretch docs this morning (Revision 2018:0621). "I never knew there was so much in it". More minor obs...
2.4. Release notes
PHP upgrade from 5.6 to 7.0
2.6. Systems administration and Symbiosis
Other configuration styles
Since jessie the restart doesn't respect happiness (automatic restart on valid syntax).
3.1. Getting started
Website config. It's worth mentioning
/etc/symbiosis/skel.d/public/htdocs/ here (incidentally, the default site contains :broken links & refers to jessie docs)
3.9. Web configuration layout
Not the case under sni (dedicated ip address not required for these log locations). Comments under 3.8 Logging might benefit from review.
4.2. SSL provider configuration
This has potential to confuse/alarm. By default we don't need to do anything.
5.16. Manually blocking incoming mail from specific sources
More of a questions -- are wildcards assumed or should that be
5.18. Setting an outbound IP for all email from a domain
5.19. Blocking email