Help please-zoom keybind remap

Hi, so my scroll button does not work very well on my razor naga 2014, so i mapped scroll to mouse button 4 and 5 below the scroll wheel. But i have to press them a lot to either zoom in and out as it only zooms the tiniest bit per press. is there a way to change it to holding it down, or further zoom per press?

Thanks in advance

Not that I’ve found. I use my mousewheel as a keybind for spells so my camera out and in is arrow up and down and I have to press each increment