I ran into this while debugging https://issues.redhat.com/browse/OCPBUGS-54692.

The error returned by this function has two concatenated elements:

1. the reconciliation error of the old and new rendered MCs
2. the first reconciliation error encountered between the old rendered MC and new base MCs

(2) was meant to be surgical about specifying the problematic base MC, but it can mistakenly catch false positives. This is because the base MCs can override each other and an earlier MC being irreconcilable to the old rendered MC does not necessarily mean that it is the issue. For example, in https://issues.redhat.com/browse/OCPBUGS-54692,
FIPS is only set to true in 99-worker-fips, and every other base MC has has it set to false. This causes the function to determine that 00-worker is the problematic base MC when the actual issue was a new MC that the user added(luks-worker). This is mostly cosmetic and should be easy to deduce from the first error, but we should fix it anyway to avoid confusion.