First let me say I agree with you 100%. Let me explain what happened in the design process.
This limitation had been carried forward for the simple fact of keeping things backwards compatible. However, this can be changed and we will reopen the discussion to change this moving forward.
In regard to the incorrect example, you are right and we will update the documentation to reflect that.
For the rain sensor type effecting the rain sensor flag itself, this shouldn’t happen. I am going to look into this and get back with you.
Thanks for the information!