ACS Skills Assessment - Employment verification

I would like to get some advice on my skills assessment situation.

My ex employer (HR) refuses to add roles and responsibilities into the employment verification letter. They have emailed me back saying that they do not endorse duties performed and that I can contact my ex-manager directly to get an endorsement directly if required. However my ex-manager provided his approval for the duties I have performed during my tenure via email.

My question is, will the employment verification letter signed by HR (without roles & responsibilities) together with my manager’s email reply in which he endorses my duties, and other documents that shows proof of employment such as payslips, promotion letters, employment contract, etc be sufficient to qualify as a valid submission ?

Appreciate your responses.

The manager endorsement is needed on a letterhead. If not letterhead, then it should be on a plain paper with notary to be eligible to be consistent for assessment.