Thank you for your comment!
Assuming this would be compatible with Adamantium 1 style DA as well?
The first version of Volition for Starknet will include L1DA and L2DA. The intention is to expand it to other Data Availability solutions, but there is no specific design yet for supporting a particular DA solution.
Also, could you decide to write to multiple cheap DA options at once rather than choosing just one, e.g., L2DA + Multiple Adamantium DA providers + Other non-native DA provider. In most cases you may not want to do this, but I can think of one or two exceptions.
Of course, it is possible to implement it at the contract level without the need for a new feature in Cairo. As Starknet currently has no specific design for more than two DA modes, there is no intention at the moment to expand Cairo to support features for more than one non-L1DA mode.