Related Clues:

• Roof worker unable to start at a future date
• See you
• Sell up, with no one succeeding
• Island in agitation before son's farewell
• Valediction
• Team's extra cheers
• Spiking non-alcoholic drink from behind, I see you
• Subsequent reform that sees Liberal rising
• Slangy "so long"
• Parting words, perhaps after the visit suggested by the starts of 20-, 38-/40- and 54-Across
• "___, amigos!"
• What a seed often has
• ''Until next time!''
• Procrastinator's time
• In future