Migrate security configs from searchguard to opendistro security

Hi,

I currently use elasticsearch oss + searchguard (for securing elk stack).
I intend to upgrade my cluster to opendistro in order to use the features available here.
We already have certain security configurations in-place like users, roles etc created & stored in searchguard index.
Is there a way I can migrate this data to opendistro_security index without having to re-create the users?

A potential way I see is -
Backup the contents of searchguard index as yaml files before upgrade.
Use the same yaml files to run securityadmin.sh in opendistro after upgrade.
– But the problem I see with this approach is -
The names of static (built-in) roles and action groups differ in searchguard and opendistro_security.

For Ex. Opendistro

all_access:
  reserved: true
  hidden: false
  static: true
  description: "Allow full access to all indices and all cluster APIs"
  cluster_permissions:
    - "*"
  index_permissions:
    - index_patterns:
        - "*"
      allowed_action

and Searchguard

SGS_ALL_ACCESS:
  reserved: true
  hidden: false
  static: true
  description: "Allow full access to all indices and all cluster APIs"
  cluster_permissions:
    - "*"
  index_permissions:
    - index_patterns:
        - "*"
      allowed_actions:
        - "*"

In my configurations stored in searchguard index, in sg_roles_mapping_yml, we are mapping certain users to existing static SG roles. For ex.

  _sg_meta:
      type: "rolesmapping"
      config_version: 2

  SGS_ALL_ACCESS:
    reserved: true
    hidden: false
    backend_roles:
    - "admin"
    users:
     - "admin"

If I use such yamls from searchguard and run securityadmin.sh in opendistro, it won’t work as expected as opendistro does not identify a static role by this name.

Is there a way to resolve this and migrate to opendistro without having to rewrite all security configurations? Any pointers would be appreciated.

Thanks!