Here is the problem: The "Close Gaps" hotkey is very useful and can save a lot of time. However, the hotkey does not work when there is a layer above or below the selected clips. This makes the hotkey unusable in many cases, e.g. if you have an adjustment layer above the selected footage. Even locking the track on which the adjustment layer is located, so that it is not/should not be affected by cuts, unfortunately does not help.
Suggested change: The hotkey should work just like "Ripple Deleat" on a selected gap between two clips... it should still work when there is a layer above the selected clips and should close the gaps between the selected clips as usual.