The rods have arrived and they seem pretty easy to use. Surface prep is important as has been noted by others - the kit I bought cam with a toothbrush sized stainless steel wire brush - the brush is very abrasive on aluminium.

Points to note so far:
The size holes you can fill is limited to about 8mm diameter in my very limited experience and as you move towards 8mm the thickness of the covering gets thinner so ends up more like a film towards the bigger holes so if pressure is involved for big holes forget it. I think I would braze a patch of aluminium over the hole if bigger than, say, 5-6mm.

If I was to be putting a patch over a large hole then I would prepare the surface around the hole and the the patch. Apply the rod to form a “puddle” around the hole and then do the same thing for the patch contact area. Finally heat the patch and hole area to get the puddles liquid so that the patch can be placed over the hole sealing it.

Ensuring the piece stays still during the cooling process is important as the filling metal stays liquid longer than I expected. My fault entirely.

For a butt joint it is better to have access to both sides of the joint to put a “weld” bead down both sides.

You can easily make smooth looking joints easily and they seem to be relatively strong - it is NOT welding so it is weaker but it could be a simple remedy to carry out a bodge repair until such time as a proper repair can be done.

The rods are lightweight and don’t take up much space so I can see myself taking some on a trip - the heat source can be from a plumbers torch so should be simple to obtain locally.

I still plan on doing a video but that will have to wait for a quiet day at work and some time to prepare samples.