For example, we would much rather state that "in some embodiments of the present disclosure, widget X may exhibit property Y . . ." than "according to the invention, widget X exhibits property Y . . . ."
From your reading of case law, is there a distinction between, "Examples of conductors include copper, aluminum, and iron." vs "Examples of conductors *may* include copper, aluminum, and iron." Similarly, "In some embodiments of the invention, conductors include copper, aluminum, and iron." vs "In some embodiments of the invention, conductors *may* include copper, aluminum, and iron." You definitely want to avoid, "The invention includes ...", but have there been cases in which a problem crops up if you don't use "may" with "examples" or "some embodiments"? Is this the same issue as inserting "but are not limited to"? One client in-house attorney insisted on qualifying practically every verb with "may".
Offhand, I am not aware of a case where a court has construed "examples of X includes Y" in the specification as limiting a generic claim to X to only covering Y. That being said, there are several cases where the recitation of "preferred" examples has limited the claims. See e.g., Wang Labs Inc., 197 F.3d 1377 (Fed. Cir. 1999); Scimed Life Systems, Inc., 242 F.3d 1337 Fed. Cir. 2001); and Oak Tech., Inc. 248 F.3d 1316 (Fed. Cir. 2001). Also, in the more recent Alloc case, the court stated that "where the specification makes clear at various points that the claimed invention is narrower than the claim language might imply, it is entirely permissible and proper to limit the claims." Alloc, 342 F.3d 1361 (Fed. Cir. 2004).
In view of those cases, I try to avoid or at least minimize any characterizing statements in the specification. That being said, I would not write "examples of conductors
may include copper, aluminum, iron . . . ." Rather, I would write, "As examples of conductors useful in the present disclosure,
non-limiting mention is made of . . . or "
Non-limiting examples of conductors useful in the present disclosure include . . . .
Also, in my view there is a fine line to be drawn between minimizing potential adverse language in the specification and complying with 112, first paragraph. One should be careful to avoid the known pitfalls in the caselaw, but one also needs to actually disclose to the public what the invention actually is, not what the invention "might be."