Increasing the TX power so that "TX Power + antenna gain" is above the regulatory domain EIRP level is illegal, or is and should be made impossible.
Wifi communication is bi-directional. (Both directions need to be possible). So the TX power needs to be balanced on both sides.
Good news is that antenna gain is reciprocal. It works for transmission and also for reception.
Because regulatory EIRP limit reduces the TX power with the antenna gain, the emitted energy in a directional antenna in the focal direction is only as strong as an omnidirectional antenna.
The practical gain in a directional antenna comes from the "antenna gain" while receiving the signal.
The Omnitik 5 ac with its 7.5 dBi antenna will have difficulties capturing a far away signal. So boosting the QRT TX-power would improve that, but is illegal.
The QRT will have no problem receiving the Omnitik signal. (Actually the signal of the (legal level) Omnitik is as strong as that of a legal QRT in the focal direction)
The legal step is to replace the Omnitik, or add a directional device to capture the QRT signal. (https://mikrotik.com/products/ptp