@Johan_Scheepers And indeed the Eu (and elsewhere in the world following same regeim) Limit…
No limit to sensitivity - again only circuit design and device physics 
So the key point is the GW can hear better hence catch a distant node, where the node cant unless also equiped with an ‘enhanced’, very large, Ant…both can radiate at same level but only one has a hearing aid! hence assymetric system if you ‘go large’ on the GW ant…add potential problems like notching or potential for beam tilt and fact you have to reduce TX power (not always obvious or easy depending on chosen GW) and you come back to fact I often post on the forum recommending stick with as close to an isotropic radiator as possible and use just a 2.1/3dbi ant, but get it as high as practical without incurring excess feeder cable losses…there is a reason why emergency services usually also stick with that for their mobile deployments
Lets leave it their, maybe I miss understood RF and how antennas work.
So you don’t have null zones,