R7000 & Directional patch 2.4 Ghz antenna

Hello,

I have a directivity trouble with my R7000 in a flat where I can not really move the router easily. In a room, the 2.4 Ghz signal level continuously varies from -78 dBi to -53 dBi. Trying to orientate the shipped antennas won't really work in that situation.

I have two 2.4 Ghz spare patch antennas and would like to know if I could put them on the router and let only one 2.4/5 Ghz default antenna on the router. Because I can't stop the 5 Ghz band, I wonder if it could be risky for the router's power amps (because of the SWR).

Thanks