Here is a link. The config file is a little bit different. I wonder if we can get this method working for the A300.
https://forum.inibuilds.com/topic/5979-thrustmaster-tca-airbus-edition-thrustlever-configuration/
I also have the same issue. It seems that if you put idle to be at idle reverse and then put idle reverse halfway between max reverse and idle it kinda helps out. Not ideal though since your throttles are not truly idle at that point.
The only way I was able to fix it was by setting the idle position to be idle reverse basically. Then putting idle reverse halfway between max reverse and idle reverse. Not ideal.