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2 dimension or 3 dimension objects, if 2d cutouts, make some sort of frame that you can support your cutouts with and use longer tek screws to tie down to roof, (have 24 *75 matrix which sits on ridge line and three supports behind it back to 3 longer tek screws -leave in roof ) i used alluminum tube 15 or 20mm i think and just flattened ends to bolt to matrix and screw to roof
you could try using tin roof antenna mounts use the existing screw holes (take screws out and re use them silicone around the holes before putting them back in), you can bend the stays to the right angle you want , you would have to run horizontal bars attached to the poles that come with the antenna mounts not too expensive