the short answer to your question is a big YES! SeoToaster is not only the most efficient free SEO & Ecommerce CMS on the market, it is also built from the ground up to serve as a front-end to multi-sites networks.
For more information on SeoToaster's multi-sites / multi-instances capabilities, you can read this comparison guide between Wordpress Multisite vs SeoSamba's multisites at http://www.seosamba.com/wordpress-multisite-review.html
For more information on SeoSamba's multisites benefits, please visit http://www.seosamba.com/seo-software.html
Hope this helps, please let us know if you have any more questions.
Thanks for using SeoToaster!