Andrea, the latest update (1.0.51) makes Charm much gentler on browsers, so the sluggishness you saw in Vivaldi should be greatly improved (it shares a root cause with the CPU change). On the missed corrections: inside Chromium-based browsers like Vivaldi, the most reliable way to correct text is Charm's Fix Selection, just select the text and press Option-Command-F. Charm now switches to that mode automatically in those browsers and lets you know when it does, so your corrections land accurately without getting in the way of the page.