Microflow validations

Hi, When would you need to perform validation in a Microflow rather than in the Domain Model? For ex. I am confused with which one from the following options: When validating objects or associations or attributes or regular expressions?
1 answers

I use the following rules while developing

  1. Only attributes to be validated & always => domain model
  2. One of the following to be validated => All in a microflow
    1. Association(s)
    2. Dependencies between attributes
  3. Validation only applicable certain processes/usertypes => All in microflow
  4. Always on one location domain model or Microflow. Never make a combination of these two