You don't need to chmod +x more than once so
chmod +x pinirq,txt in unnecessary (and will fail
because crontab has no idea where pinirq.txt is located)
Not sure about crontab and sudo
(will it ask you for a password during startup?)
So the systemd method of launching scripts at startup
may be better
Note that sudo ./pinirq.txt eth0 will fail because again crontab
does not know where pinirq.txt is located (you need a full path
or copy pinirq.txt to a standard executable directory like /user/bin/
Also pinirq.txt should probably be renamed just pinirq or pinirq.sh
(it only has the .txt suffix because that's required to be able to post it to the forum)
@reboot is what tells crontab to do the operation only at boot time
