Configuration file where I tried one line at a time.
[main]leftmeta+tab = leftcontrol+leftmeta+right #leftcontrol+leftmeta+right = leftmeta+tab#leftcontrol+tab = macro(leftcontrol+leftmeta+right)None of what I've tried works or makes any difference on my machine. I've also run sudo keyd reload every time.
The documentation at man keyd is a little bit confusing but from what I understand, this operation should work with macro().