Question about Netmetal 5 triple

Hi there
I have mikrotik netmetal 5shp triple RB921UAGS-5SHPacT-NM with my hand , I create custom image for it but I have questions about its chain its have 3 chain and I want to connect it with ubnt omni 5ghz 13 dbi 2 chains only , my Q is it work fine if I use only 2 chain (netmetal) and should I disable 3rd chain from software ? How ?


Any suggestion

Any idea ?