I love the synchronization feature, and use it almost weekly - sometimes multiple times a week. This is due to reinstallation of either Opera or the operating system, which is a separate matter entirely - comments suggesting I should avoid reinstallation will be unwelcome.
Can anyone provide the location where Opera stores the variable that toggles Mouse Gestures option in Settings under Shortcuts? I have scripts that greatly ease reconfiguration of many things, but I have not been able to locate this variable even with sysinternal's procmon.