I used acars way back in one of it's various offerings, wacars, jacars, posfix etc and it was fine for tracking although the positional reports were much less frequent.
It was possible to predict to the course, speed etc and produce a moving track. All a bit Heath Robinson compared with todays Radar but fun nevertheless.
Airnav have already got all the necassary knowledge and experience - just wondered whether integration was possible. Something that may fill in some of the gaps without having go down the plane-plotters route.