Did knocker-uppers have any interactions with other professions or trades?

Yes, knocker-uppers often had interactions with other professions and trades. They often worked closely with police officers, as they would wake them up for their early morning shifts. They also had interactions with bakers, who would need to be up early to start baking bread. Knocker-uppers may have also had interactions with night watchmen or milkmen, who would be finishing their shifts as the knocker-uppers were starting theirs.