At WoodSolutions we have a number of 'generic' fire reports, ie. they can be applied to different combinations of standard wood-based materials regardless of brand names. For example, Regulatory Information Report RIR 45982.13 titled Fire Hazard Properties of Timber Veneers on Standard MDF and Particleboard Substrates in Accordance with AS5637.1:2015 covers any type of wood veneer up to 1120 kg/m3, applied to MDF or particleboard of 6mm minimum thickness - refer Table 4.

We don't have any experience of sourcing Darwin stringybark, nor of fair trading considerations, as it is not a major commercial species - at least in the southern States. We assume it will be used unseasoned since a column of any significant size would take quite a while to dry. During the drying process shrinkage is likely to be of the order of 5% (across the grain, negligible lengthwise). It's also advisable to avoid the centre when sawing the log as material close to the centre is inclined to split.

We don't have design data for TTE hybrid products but it's possible Greg Nolan at the University of Tasmania might be able to help. Greg is a professor at the UTAS School of Architecture & Design and you will find more about his background via this link https://discover.utas.edu.au/gregory.nolan. 

Red ironbark is one of the seven timbers that have passed the test in AS/NZS 3837 to be classed as bushfire-resisting and therefore is suitable for external exposed elements up to and including BAL-29 (eg. wall cladding, decking, etc).