after some time I found the solution... the key is to use absolute path for all apps involved.
crontab:
@reboot wendhausen /Volume1/User/wendhausen/\[raid\]/\[system\]/onboot.sh ps3netsrv
script:
/Volume1/@apps/Tmux/sys/bin/tmux new-session -d -s onboot '/home/wendhausen/[raid]/games/Playstation/ps3netsrv_linuxX86_64 /home/wendhausen/[raid]/games/Playstation/ 38008 *.*.*.*'
now it is scalable.





