Are any Homeric characters attested in evidence contemporary to the supposed timeframe the events to?

The simple answer is: no, none at all. A few names that pop up in Greek myths dating to the classical period do also appear in Bronze Age texts, like the individuals named a-ki-re-u (*Achilleus) in KN Vc 106 and PY Fn 79.2, but they’ve got absolutely nothing to do with the legendary character — they’re both in the wrong parts of Greece, for a start, and they’re not warrior-leaders.