Our team's policy at the competition is to disclose anything that is remotely questionable to the inspectors at the time of inspection, allowing us time to fix it if they are going to object.
Last year, we had
this on our robot, and specifically pointed it out to the inspectors with a discussion of how the rules applied. It created a bit of consternation, but ultimately was allowed based on how we were using it.
The worst time to find that a part is disallowed is when your bumper comes apart during the competition, revealing 20lb of air entrained concrete
. No time to remediate.