Given you’re already using JOSM to do the conflation, I have a few custom JOSM rules for validating and expanding common street and address abbreviations (St → Street etc). Here’s one, but there’s a few more in the repo: josm-validator-rules/rules/USStreetNameExpander.validator.mapcss at main · watmildon/josm-validator-rules · GitHub
You may also want to add the MapWithAI plugin to your JOSM install as it has a good validation rule that will show addr:street tags that don’t match up to nearby streets. Very useful for finding street name or addr:street typos.