Hi,
got an answer today from JustFlight about the Altitude Hold.
"Hi,
Thank you for your email.
As this is not a feature of the real aircraft, we have only added this in for convivence, we do not have current plans to look into this.
The aircraft is completely capable of flying level when trimmed correctly.
Kind regards
Craig
Have a JF/JT account? Check your ticket online at https://support.justflight.com/helpdesk/tickets/50963
Simply log in with your Just flight Account!"