Yes s3 audios are now supported . If you are using wplms s3 plugin for your audio files in unit ,then they will work fine in wplms app .We do added support for this recently .
Well subscriptions are not integrated in app right now .
For woocommere subscriptions we need to add the support in the wplms api first .
However wplms inbuilt subscriptions support will be added soon .As you may know that there is setting in course product settings to enable subscriptions . We will be adding support for that in app very soon .
And for woocommerce memberships too .