application_restriction.rb

class ApplicationRestriction
  include Virtus.model(strict: true)

  def to_module(&block)
    restriction = self
    mod = Module.new do
      define_singleton_method(:inspect) do
        "#{restriction.class.name}(#{restriction.attributes})"
      end
    end
    mod.class_eval(&block) if block_given?
    mod
  end
end

ready_at_time_restriction.rb

class ReadyAtTimeRestriction < ApplicationRestriction
  attribute :ready_at, TimeWithZone

  def to_module
    restriction = self
    super do
      define_method(:ready?) do
        if restriction.ready_at.past?
          super()
        else
          false
        end
      end
    end
  end
end

thing.rb

class Thing < ApplicationRecord
  after_initialize do
    if restrictions.any?
      # Look through restrictions, create appropriate classes which craete modules and prepend
      # Normally the ready_at time would be in the restrictions json,
      # you wouldn't actually do 10.seconds.from_now here, but it's just an example.
      restriction = ReadyAtTimeRestriction.new(ready_at: 10.seconds.from_now)
      mod = restriction.to_module
      singleton_class.prepend(mod)
    end
  end
  
  def ready?
    true
  end
end