Workaround which works well enough for me:

• Tab Pinner to obtain the Ctrl + Shift + X keyboard shortcut to pin / unpin a tab: https://chrome.google.com/webstore/detail/tab-pinner-keyboard-short/mbcjcnomlakhkechnbhmfjhnnllpbmlh
• When I want to close a pinned tab ==> - Ctrl + Shift + X followed by Ctrl + W (when you get the hang of chaining the two it's pretty quick. At least much better than right clicking on the pinned tab)

Hope this helps