Compact Budget Build that is a bit different

Do you have a link to the item you purchased ?

What do you normally use a fresnel lens for ?

yep, just ensure to select the size you need as this link has multiple options https://a.aliexpress.com/_mr9yu5E

they are basically a normal lens that has been segmented so the refraction angles are the same but the unnecessary thickness is cut out of the middle (making it much thinner). used in projectors, lighthouses, some headlight covers, screen/reading magnifiers. many are circular, for sims we need a linear lens

what size monitors do you use ?

AOC C24G1 24" Curved Frameless Gaming Monitor

FYI, I'm not sure cutting a lens to make 2 is the best approach. While it worked for me I am just guessing and suspect the best may be to get a lens of the optimal width and focal length, but figuring that out would be the tricky(and potentially costly) bit.
It is tempting to try some 300 x 30 x f12 lenses but the trouble is it is a gamble as it might be better, or could be no good at all.
It is a tricky to estimate, these things work in mysterious ways as they seem to overlay the refracted image with the native image behind so I struggle to predict the outcome - I just swapped the positions of my half lenses (cut edges now on main screen) and they work better than the way I originally set them up ???? While they now cover more of my center screen, the center image is less distorted (stretching/doubling) with only a tiny bit of doubling on the side screens(which may be due to a small gap between lens and screen)
If anyone else has a go at this with different lenses it would be interesting to hear results

Did you cut the lens in half so its now half the width ?

yeah, split it down the center

Almost exactly one year on, my lever arm succumbed to fatigue. Pretty good considering it was just a trial piece made out of scrap to prove the concept.

I might patch it up but if i do the risk is my temporary repair might be as far as i go... I really should rebuild it properly without using slotted shelf racking - those slots are the stress risers that killed it