S3 (settings/apps) + B2 (files)?

I’d like to host Nextcloud on AWS. I know that it is possible to use S3 or B2 as the primary storage backend using the following in config.php:

  'objectstore' => array(
        'class' => 'OC\\Files\\ObjectStore\\S3',
        'arguments' => array(
                'bucket' => 'bucket-name',       //add your bucket name here
                'key'    => 'keygoeshere',       //add S3 bucket user/admin key here
                'secret' => 'secret-goes-here',  //add S3 bucket user/admin secret phrase here
                'use_ssl' => true,
                'use_path_style'=> true,       
                'region' => 'us-east-1',  // Essential to get S3 workings

What I would LIKE to do is use S3 for the storage of all Nextcloud resources (like app resources, settings, etc.) but use B2 for storage of actual files. I tried using B2 as primary storage, but it is pretty painfully slow just to log in and use Nextcloud. S3 is faster since it is also an AWS service. Ideally, I’d like to put any Nextcloud/user data in S3 but use B2 to store actual actual files since it is so much cheaper.

Is there a way to do this?