Choose the experience you want
Wli and Afadjato answer different wishes. Wli puts a waterfall at the centre of your outing; Afadjato makes the climb and the hill setting the attraction. If you've only one free day, pick the experience your group wants most instead of assuming both are essential.
Don't read “waterfall” as a promise of an effortless visit. Ask about the exact route, current conditions and the time your group should allow.
Let the least enthusiastic walker speak first
A shared day can unravel when the strongest walker chooses for everyone. Ask each person how much climbing they actually want. If preferences differ, choose one common activity and save the other for a separate trip.
Compare Wli Waterfalls and Mount Afadjato from your accommodation, including the return. The drive is part of the available day.
Protect the finish
Arrange food and a return pickup before adding a second stop. A climb or waterfall walk is less enjoyable when someone is worrying about a missed meal or a driver who hasn't been contacted.
If you're staying another night, keep the next morning open as an alternative. Weather and energy are good reasons to change the plan. Completing one outing with time to enjoy it is a stronger use of a short visit than hurrying through two.