Can we freeze a HELOC just because the customer requested a payoff?

Posted too soon, found my answer in a previous question:

There are six circumstances in Regulation Z § 1026.40(f)(3)(vi) under which a creditor can prohibit additional extensions of credit or reduce the credit limit applicable to any [HELOC] agreement. None of them involves doing so in connection with having provided a payoff figure for the account. Any payoff statement for such an account should include a disclaimer as to the date through which the payoff has been calculated and that it is subject to any balance changes occurring after the statement is provided.