Andrew, thanks for your response. I am an experienced FB admin on multiple pages and I know how to Admin pages from native FB. But one of my fellow Admins does 90% of their web browsing and FB posting from their Smartphone and since Safari is the standard Smartphone browser, we were hoping that there might be an option to allow for multiple targets on a FB post. And to be clear, it's not simultaneous update we are looking for, just the ability to define targets other than the poster's personal FB page. So each update would still go to only one page but the user would have the ability to change their ID dynamically (like you can do on native FB).
It sounds like Safari just isn't capable of this type of flexibility so am open to other suggestions that allow browsing on the web AND the ability to post using different FB identities.