Thanks - did not know about this TCC_RT!
At first glance:
TCC-RT also does not support command dialogs, interactive command line input & editing, or the PRE_INPUT, PRE_EXEC, and POST_EXEC aliases. See README.TXT in the TCC-RT installation directory for more details on TCC-RT.
makes me thoughtful as I have dialogs in my system. I'll dive deeper into it.