What are the options for solving this problem with the slider?

Question

css

Good afternoon, tell me how to solve this problem: you need a slider whose central slide would be 800 peaks, and the rest (2 on the side) had a smaller width and were half (see codepen), well, they were vertically in the center of the parent, in principle, this task solved, but the problem is different. I now have the effect of going forward and a carved return back on the slider. If you make all the images the same width - there is no problem, everything is smooth and beautiful. Is there any way to solve this problem on this slick slider? Or throw ready option if you have links to them. Codepen.io