memo.md

これでL.Control.Opacityは使える

//MIERUNE MONO
const m_mono = new L.tileLayer("https://tile.mierune.co.jp/mierune_mono/{z}/{x}/{y}.png", {
    attribution: "Maptiles by <a href='http://mierune.co.jp/' target='_blank'>MIERUNE</a>, under CC BY. Data by <a href='http://osm.org/copyright' target='_blank'>OpenStreetMap</a> contributors, under ODbL."
});
m_mono.addTo(map);
L.control.opacity(m_mono, {label: "mierune mono"});

// 追加
var opacityControl = L.control.opacity(layer);
opacity.addTo(map);

// 削除
opacityControl.remove();