I hate CLAs. I understand why they exist. I find them obnoxious barriers to getting trivial bugfixes accepted.
Even gcc before dco, accepted small bug fixes without a copyright assignment.
Small/non copyrightable changes didnt happen that much; maybe 10 over 20 years.
We(GCC) have been getting more recently (this year) but with dco there is less worry. And we just point to the dco documentation.