I hope I am not putting an experts hat here, because I am not one of those. With that said,
Your statement is so generalized and using words like phrases and clauses which have different meaning depending on whom you are talking to. So keep the definition simple. An ed modifier is a past participle phrase acting as a modifier.
From your posts I understand that there is a general confusion on different type of phrases.
I would suggest you to go to following link( or refer any good resources on English grammar):
https://grammar.ccc.commnet.edu/grammar/phrases.htm
Modifiers need not be all the time single words and they tack onto "pre" and "post" modifiers but still retain their main characteristic. Identifying an
head word helps to understand what type of a phrase it is and how it is behaving. Sometimes, it is easy to how it is modifying and understand what type it is.
Coming to participle phrases, consider another example ( quoting from the link:
https://www.english.ucalgary.ca/grammar/ ... e/2_4d.htm )
Examples:
That dog keenly hunting the ducks must be a thoroughbred.
participial: hunting
object: the ducks (the D.O. of the participial)
modifier: keenly (an adverb modifiying the participial)
participial phrase: keenly hunting the ducks
Hidden by the trees, Jerry waited to scare Mark.
participial: hidden
modifier: by the trees (a prepositional phrase
modifying "hidden")
participial phrase: hidden by the trees (an adjective
modifying "Jerry")