Yes we provide full support for RIA data services.
The approach we are using is really similar to what Entity Framework provides however the two approaches are not compatible with each other. Having said that if you decide to use OpenAccess for your model you will not be able to convert it to Entity Framework in any other way but starting over.
Please be aware that we provide solid support and we aim to quickly resolve any customer issues in case such appear so you should not have any blocking problems.
I hope that my answer has been useful to you.
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