NR7101 external antenna add-on

Hello.

I have NR7101 but i have the following problem:

there are two towers available near me, one 1 km away with only b3+b20 and another 3 km far away with b1+b3+b20+N78. Now in auto mode 7101 aggregates b3+b20 from tower near me and n78 from far tower but n78 have poor RSRP. Sometimes can aggregate B1 from far away tower (-120 rsvp) too. If i turn antenna in direction of 5G tower n78 will be little better (from -103 to -95) but b3 & b20 get very worst.

My idea.. buy one external antenna dedicated to 5G N78 from Kaser with 15dbi gain, connect it on 7101 board, leave 7101 pointed to 4g site and external antenna 5g pointed to 5G site.

My question is:

there are 7 antenna ports inside, which two are for 3700 MHz?

Can my idea work?

thanks to all!