do we need to disclose HOA fees on an LE?

If you know about them - yes. Your LE has to be issued in good faith whether it includes services required by you or otherwise.

Are HOA fees included in escrows on HPML loans?

If you want them to - sure. Only taxes and insurance are required under 1026.35 however:

(b) Escrow accounts. (1) Requirement to escrow for property taxes and insurance. Except as provided in paragraph (b)(2) of this section, a creditor may not extend a higher-priced mortgage loan secured by a first lien on a consumer's principal dwelling unless an escrow account is established before consummation for payment of property taxes and premiums for mortgage-related insurance required by the creditor, such as insurance against loss of or damage to property, or against liability arising out of the ownership or use of the property, or insurance protecting the creditor against the consumer's default or other credit loss.