Be careful using real Bondo- the automotive body filler - as sold in the US - on soft wood. On mdf or harder woods it's ok. it's meant to be used on metal substrates and sets up pretty hard. on soft wood you risk digging out wood around your patch when you try to sand it, because the wood is much softer than the filler. Consider using a 2 part filler made specifically for wood that sets up just a little softer. I think they even make a wood version of Bondo. I can't see exactly what Ond is using but its probably an Aus. specific product- different countries have different environmental rules, etc. YMMV. experiment a little and find the best product for your project materials and techniques.
Really enjoying these videos from the Man Down Under. I love to be shown a project going through all the steps.