Conditional plugin load

Hi! This question is mostly because of educational purposes, so not a real issue. Still, the problem is the following. I was looking in a ways to decrease memory consumption and tried to implement conditional loading of this gem and yabeda-prometheus gem based on environment variable. So it look like this:

Gemfile

gem "yabeda-puma-plugin", require: false
gem "yabeda-prometheus", require: false

config/puma.rb

if ENV.fetch("ENABLE_YABEDA", false)
  require "yabeda/puma/plugin"
  activate_control_app
  plugin :yabeda
end

routes.rb

  if Settings.yabeda.enabled
    require "yabeda/prometheus"
    mount Yabeda::Prometheus::Exporter => "/metrics"
  end

but all attempts to require these gems manually lead to this error:

require "yabeda/puma/plugin.rb"

NoMethodError: undefined method `already_configured?' for Yabeda:Module
from /Users/khataev/.rbenv/versions/2.7.7/lib/ruby/gems/2.7.0/gems/yabeda-0.11.0/lib/yabeda/railtie.rb:7:in `block in <class:Railtie>'

# or

require "yabeda/prometheus"

NoMethodError: undefined method `already_configured?' for Yabeda:Module
from /Users/khataev/.rbenv/versions/2.7.7/lib/ruby/gems/2.7.0/gems/yabeda-0.11.0/lib/yabeda/railtie.rb:7:in `block in <class:Railtie>'

# or even

require "yabeda"
NoMethodError: undefined method `already_configured?' for Yabeda:Module
from /Users/khataev/.rbenv/versions/2.7.7/lib/ruby/gems/2.7.0/gems/yabeda-0.11.0/lib/yabeda/railtie.rb:7:in `block in <class:Railtie>'

not sure to understand how everything works when those gems are loaded by bundler, but looks like there is something non-trivial around yabeda gem require (on which those two depend). Can you please explain?

yabeda-rb / yabeda-puma-plugin

Conditional plugin load #28