I made my own authentication forms using ash_authentication as basis so I have more flexibility especially when it comes to styling. It works for almost everything only the validations does not work for :request_password_reset_with_password. I set up my form like:

    form =
      AshPhoenix.Form.for_action(User, :request_password_reset_with_password,
        api: Account,
        as: "user",
        context: %{private: %{ash_authentication?: true}}
      )
      |> to_form()

And it does enter my validate form:

  def handle_event("validate", %{"user" => params}, socket) do
    %{form: form} = socket.assigns
    form = AshPhoenix.Form.validate(form, params)
    {:noreply, assign(socket, form: form)}
  end

where user has a validation on email:

  validations do
    validate match(:email, ~r/(^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$)/) do
      message "must be a valid email address"
    end
  end

And which also works for the registration form so Im not sure what Im doing wrong. Only resource I found was a discord archived support page where it was said to use:
context: %{private: %{ash_authentication?: true}}. But all of the examples of what Im trying to do can just use the validate and it seems to work, although using a bit of a different setup so if more information is needed let me know.