Hello,
The differentiation of antenna connector pairs is important, if you intend to use it with devices, which only support 2x2 MiMo, but have two separate radios, only one of which is used at any time instance. From Teltonika catalogue of products, RUTX12 would utilize such antenna configuration, and labeling of the pairs would mater, as it has two modems, each with two antenna connectors.
In case of RUTX50, since it utilizes 4x4 MiMo, all of the antenna channels on the device have a differing purpose, thus, it only matters to have all of the connectors attached.
Best regards,