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.