ActiveModelSerializers :camel_lower configuration not working

I want to leverage AMS to create json data to pass as GraphQL variables in my test suite. Apparently, it support :camel_lower which would convert hash keys like :some_field to :someField but I can't seem to get it to work. Here's the relevant code:

/config/initializers/active_model_serializers.rb:

ActiveModelSerializers.config.key_transform = :camel_lower

/app/serializers/service_serializer.rb:

class ServiceSerializer < ApplicationSerializer
  attributes :id, :name, :time_increment
end

rails console:

ActiveModelSerializers.config.key_transform
 => :camel_lower 
s = Service.new(name: 'Test', time_increment: 10)
 => #<Service id: nil, name: "Test", time_increment: 10, created_at: nil, updated_at: nil> 
ss = ServiceSerializer.new(s)
 => #<ServiceSerializer:0x00007f3771dd9dc0 @object=#<Service id: nil, name: "Test", time_increment: 10, created_at: nil, updated_at: nil>, @instance_options={}, @root=nil, @scope=nil> 
ss.as_json
 => {:id=>nil, :name=>"Test", :time_increment=>10} 

The result I was expecting was:

 => {:id=>nil, :name=>"Test", :timeIncrement=>10} 

ActiveModelSerializers has been in some sort of maintainance state for a long time and doesn't seem to be receiving any updates.

My personal choice has been either the blueprinter gem or jsonapi-serializers. The blueprinter one is closer to AMS.

It is very easy to work with

# Gemfile
gem 'blueprinter'

and the usual

bundle install

Creating a serializer is very straightforward

# e.g. app/blueprinter/service_blueprint.rb
class ServiceBlueprint < Blueprinter::Base
  # identifier :id

  fields :id, :name, :time_increment
end

Add a class LowerCamelTransformer

# e.g. app/blueprinter/lower_camel_transformer.rb
class LowerCamelTransformer < Blueprinter::Transformer
  def transform(hash, _object, _options)
    hash.transform_keys! { |key| key.to_s.camelize(:lower).to_sym }
  end
end

And in config/initializers/blueprinter.rb

Blueprinter.configure do |config|
  config.default_transformers = [LowerCamelTransformer]
end

Test it

s = Service.find(1)
puts ServiceBlueprint.render(s)
# Will give you a nice output with lower camel case