In RH 2017, we have 4 layouts that are shipped as part of the product - Azure Blue, Charcoal Grey, Indigo, and Ocean.
Are there any additional layouts available anywhere/downloadable?
How easy/complex is it to customize Indigo and Ocean layouts? Our requirement is to go frameless but customization should be easy for the documentation folks to do.
Any Dos and Don'ts/best practices/known issues when customizing layouts?
There are further layouts at HelpEssentials
Beyond the customisation provided in the output, it becomes highly skilled.
See www.grainge.org for free RoboHelp and Authoring information.