Have you considered changing CMAC settings in your installation?
It is long time ago I used TLIB last time, maybe 10 years, but I believe tab size was configurable. I guess you refer to tab compression so spaces are converted to TABs at input. Turn if off or configure TAB size at TLIB side proper way. In any case, do you really believe a problem with 3rd patry software should be the reason to change default settings for MEW native macro language?
If I haven’t comprehended your problem correctly, try to explain it again, please. Not everybody has experience with TLIB and some of us even don’t use Word.