Disable xrender at startup

I'm having a similar issue to the one described here: https://www.mathworks.com/matlabcentral/answers/373897-external-monitor-throws-java-exception

Basically, I'm running a network installation of Matlab 2018a in Linux and using NoMachine as my desktop. Whenever I resize the NoMachine window (which sometimes happens by itself), I get the lengthy Java error described in the link above.

I would like to try the solution described in the link, basically deactivating xrender, but I cannot create the file

/usr/local/MATLAB/R2018a/bin/glnxa64/java.opts

because I do not have permission to this folder. Is there a way to place the file elsewhere, and have my startup.m point to it so that it gets called when I start Matlab? Or is there another way to deactivate xrender from the Matlab command window?