Talking of crushing the ends of the tubes it is possible but you have to Aneal them about 4 times to get them to flatten without cracking
I use a simple methoud on mine
First rub some soap (normal hand soap is idea) onto the end of the rod
Then gently heat the whole area that you want to bend/flatten
When the soap starts to burn (turns brown/black) you have reached a safe anealing temperature for the alloy
Don't get it any hotter as it will melt and ruin the bar
Gently tap it into shape with a clean faced hammer and blocks of wood
When the alloy starts to harden (it feels and sounds different) re-heat and start tapping again
It normally takes me 4-5 heats to get the bars flat ( I place a 3mm x 16mm strip in the middle to leave a gap so the ends don't fracture
You can see the finished item below
Jason