If Quick Find is capturing your keys/typing-ahead, then you can alter the Quick Find settings via the about:config page.
You need to know which settings to change in about:config though.
I googled "disable Quick Find in about:config" and found some good guidelines - e.g., here: How To Disable Firefox Quick Find
From experience, if you play around with the about:config settings you can pretty much tweak anything in Firefox. When you have made a change, the line of settings becomes emboldened.
If you want to undo the user changes, just double-click the emboldened settings.
I always take care in about:config because you can change/restore settings leading to unintended consequences if you alter the "wrong" ones by mistake.