As far as I know it can work in Medium Trust. If you posted an error which you think is related please link top the post.
The setting in Web.config eliminates all calls to the dotnetopenauth.dll from being executed. If you disable it in Web.config and it stil throws an error related to that dll you can also delete the dotnetopenauth.dll from the bin folder. This is what I do for the Mono packages because it can't work on Mono.
mojoPortal works fine in medium trust in general following the steps outlined in the documentation http://www.mojoportal.com/mediumtrust.aspx
If they don't allow outbound web requests then the Feed Manager may not work and OpenID may not work, but there is no need to make a separate package just for corner case hosting situations. These issues can be resolved by configuration or not using the features that don't work.
Hope it helps,