Be careful !
QRT has antenna gain of 24 dBi , with TX power on 27 dBm you have a beam with energy density of 51 dBm , this is a beam with the power density like a 100 Watt omnidirectional transmitter (EIRP).
(Your microwave oven is 57 to 59 dBm omnidirectional inside).
Legal limits are usually around 30 dBm (1 Watt EIRP). ROS will not allow you to set a lower antenna gain parameter than the gain of the built in antenna. If you still can hack it to full radio power , you work illegal, and close to the unit you risk your eyes (Cataract). (It’s like playing with a class 3 (or even class 4) 200 mWatt laser pen with invisible light)