The second patch just released for RH2015 includes the creation of a sitemap for your WebHelp. My understanding is that Google looks for site maps to aid it in searching your site & promoting your ranking.
Thank you very much for the response.
My understanding from our developers is that this would help to a degree, although it would still (apparently!) leave the issue with the somewhat verbose html.
Thanks again for your help
Note that this only applies to the most recent RoboHelp version. The initial post indicated RoboHelp 10. And Multiscreen output is a bit of a Hydra with loads of files created as it repeats the help system for each screen profile defined.
I'd definitely investigate RoboHelp (2015 Release) and opt for Responsive. I believe that's where the sitemap will come into play and it should also dramatically reduce the number of output files.
Brilliant - thanks Rick