Ok to remove plastic bracing?

[FishyFishy!]

In my new build, I have decided to go with a heavy duty utility shelf to stack my sumps on. The problem is the one I want is almost exactly 48". All of my tanks have the plastic rimmers on the top and bottom, making them 49".

I have has rimless tanks before that were DIY, and they did just fine, but these tanks are larger. I have two 80 gallons and a 90 gallon used as sumps. (first one fuge, second skimmer/reactors/media, third filled with live rock.

Will it be ok to de-rim these tanks to make them fit? Do these plastic rims even serve a purpose other than looks or protection?