Creating a variant for an attached entity does not allow a custom key, it automatically sets a key:
attached_entity.variant(resize_to_limit: [200,200]).processed.url
=> "https://storage.googleapis.com/my_bucket/t6lgob4eat2lka1y4s27n3rjfwt3"
We could expose the process method
and allow it to receive a key, so I can set the path where I want the variant to be placed.
I’m really hoping that some work in general can be done on ActiveStorage to allow for deliberate naming and accessing of cloud stored items.
I use a screenshot API that really helpfully places output direct into S3 buckets. To turn this into an ActiveStorage object requires a bit a hackery where it should be so simple.
Is there a reason why adding custom keys is being managed so restrictive?
Another problem I’m thinking of is that the variant, although when using a processor like vips for images does not get the proper content-type appended. Thus, browsers are forced to download instead of initially displaying the image in the browser. => Forcing more traffic then necessary. On the scale this plugin is used this might be a huge amount. 
At least when using the storage service in public mode.
I had issues with content-types too, same lack of control