legality of wheels on outside of frame

[ferrari77]

this year our team decided to go with a custom sheet metal WCD drivetrain

the outsides are sheet metal C channels with the wheels on the outside

from the top it would look like this

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The Frame Perimeter definition in R02 says it must comprise "fixed, non-articulated structural elements."

I have see many teams do a WCD style drive and have metal portrusions along their chassis that stick out past their wheels in order to mount their bumpers. as long as the portrusions support the bumpers every 8 inches does this comply with the rules?
we don't have enough space to mount the wheels on the inside of our drivetrain so if anyone can confirm that this is legal or provide suggestions of how to legally mount bumpers it would help a lot

if you want pictures I can upload some of the cad of our chassis

thanks