The question actually concerns adjuncts. Adjuncts are optional constituents that can be removed from a sentence without rendering the sentence ungrammatical. The modifiers mentioned in the question are adjuncts for the most part and can hence be removed from the sentence without causing the sentence to become ungrammatical. The term modifier and the term adjunct overlap in meaning and use. However, the extent of the overlap may or may not be complete.
Another example can help make these notions clearer:
(1) Yesterday, we repeatedly attempted to visit the new brew pub in our neighborhood.
The bolded constituents are all adjuncts or parts of adjuncts. They can be omitted from the sentence without causing ungrammaticality:
(2) We attempted to visit the pub.
If any of the other words are omitted, however, the sentence becomes incomplete and hence ungrammatical, e.g.
(3) *We to visit the pub.
(4) *We attempted visit the pub.
(4) *We attempted to the pub.
(5) *Attempted to visit the pub.
(6) *We attempted to visit.
(7) *We attempted to visit pub.
Based on the examples, we can conclude that each of the words We, attempted, to, visit, the, and pub is NOT an adjunct or part of an adjunct.
Note how the determiner the behaves in this example; it cannot be omitted, which indicates that it should NOT be viewed as an adjunct. I think many grammarians would, however, view determiners such as the as modifiers, so we see that for these grammarians, the overlap (adjunct vs. modifier) is indeed not complete.
Concerning the DG analysis of these matters, many DGs distinguish between arguments/complements and adjuncts/modifiers in their inventories of syntactic functions. We see an example of this in the question where the functions nummod, nummod, advmod, and advcl are mentioned. These designations are clearly those of adjuncts.
A word or two of caution are also appropriate. The answer here is simplifying matters somewhat, for there is a further important distinction, that between obligatory and optional arguments/complements. An optional argument can be overlooked and incorrectly taken to be an adjunct. Yet another important point is that the adjunct vs. argument/complement distinction is not unique to DG; it exists in most theories of grammar.
In sum, the answer to the question is "Yes", although there are certain caveats to be aware of concerning the use of terminology.