General/limited Proxies in Maryland

If the "general proxy only" restriction is in your charter or bylaws, then IMO it would be allowed under 5-202(b)(7).

Article - Corporations and Associations
§5–202.
(b) Notwithstanding any other provision of this article, the charter or bylaws of a nonstock corporation may:
(7) Deny or limit the right of its members to vote by proxy.

Bill,

Your Association is governed by various documents.
Briefly, these are:

The Declaration of Covenants, Conditions and Restrictions (also called CC&Rs or Covenants). These are restrictions attached to your deed and is considered the contract all homeowners agreed to abide by. This is also the document that creates the Association. This document is recorded at the County property office or court house.

The Articles of Incorporation is the document that incorporates the Association (Association, INC.). This document is filed with the State Corporation Commission.

The Bylaws is the document that specifies how the Association is to run. State Statutes specify some (well, the minimal) items that must be contained in the Bylaws. Bylaws may or may not be recorded with the CC&Rs (typically condominiums do this and HOAs do not).

Resolutions are formal written decisions by the Board. Resolutions typically clarify issues and procedures related to the other documents (example: Assessment collection process and definition of commercial vehicles), establish rules for common areas (example: parking policy, pool rules, etc.) and any architectural guidelines. Resolutions are internal documents to the Association and are typically not recorded with anyone but should be published to the membership.

Bill

It is not uncommon for Articles of Incorporation to say so and so...like proxies are allowed...unless the corporation's bylaw say otherwise. Very common in states (like SC) where they take a hands off approach to how a corporation operates.

Bill

From the link:

(5) Provide for the number or proportion of voting members whose
presence in person or by proxy constitutes a quorum at any meeting of its members;

(6) Provide that any action may be taken or authorized by any number or
proportion of the votes of all its members or all its directors entitled to vote;

(7) Deny or limit the right of its members to vote by proxy; and

It appears they can use proxies to establish a quorum and limit the use of proxies
to general proxies only.