We have plans to launch on the Ethereum 2.0 network, in the future. But have no immediate plans to support any other networks. The Symmetric DAO will be following the market closely and could choose to support more networks in the future.
How do I propose a new network to be supported?
You should join the Symmetric DAO and raise a proposal to the DAO members to vote on. Before doing that it would be helpful if you also joined the Symmetric Discord group and raised the subject for informal discussion to measure community sentiment before formally raising the proposal.