The thrust line is critical if you really want a near neutral aeroplane. I have flown lots of these Hawks, test flown 10+ and the thrust angle on all the production aeroplanes is much better than my own model. None of my circle of Hawk flying friends have mentioned any concerns, though I have advised on turbine mounting on most of these. Mixes are not as good as a correctly set up "mechanical" thrust line. So many things affect it (flaps in the Hawk vary on neutral-by peoples building) but there is no reason why it can't be near perfect. I'm guilty of not coming back to this and placing something in a manual addendum...so I'll do it!
I will have another Hawk to test fly in the next month, so I'll concentrate on how it behaves, it will have a P-140RX for power.
Mixes rely on timing, everyone has different throttle action habits, speed etc.

Lets get a fixed number for the front of the pipe from the fuselage top centre line (its the easiest datum) and then everyone can work from that.

Dave