@User sorry for the delay. The xschemrc i have provided is supposed to be used launching xschem from the directory where xschemrc is located, so yes, a better xschemrc uses absolute paths (may be with some shell variables $env(VAR) ) , but this depends on final installation.

tcl_files

is a list of scripts to load at startup. Again in a final installation this should also be a (absolute path) list of tcl files (possibly with some shell/tcl variables) , BUT it is not related to the

XSCHEM_LIBRARY_PATH

which is used to find .sch / .sym files.