I will split this topic into Posts and Pages because the results differ..
Posts: These work with Yoasr and Smart Crawl. It took me awhile to learn how to ge rid of that ARCHIVE backgound image. >edit post>view post>upfront.> no archieve image. Then go to the "...." To remove the background image. Is there an easier way?
Post content can be edited on an iPAD. I don't think this would include all content like images, but OK.
Pages are a differnt matter for the SOE plugins.
When I use the WP editor to change content then Yoast shows the word count change etc. But the actual page content in Upfront does not change. When I edit the page content in Upfront, the Yoast plugin does not reflect a change. Now I suppose I could edit the page twice.. In Upfront and again in WP. But I have yet to confirm the meta info for the page actually changes when I use teh SEO plugin..
But this also means that page content can't be edited with my iPad.
Sorry if this is long and not very clear.
BTW, my thanks to Jenni McKinnon for the article on How to Create Separate Blogs on a Single Install of WordPress