I wonder if you can help the user move between a 'must have' filter (like on the left) and a looser 'pefer' filter, like choosing an area of the chart (like Select in paint apps.) Maybe it could be as simple as changing the checkmark/slider options to have 3 values: null, must, prefer. For example, check a few CPUs as your required spec, but also a few others as the prefered.

Like/dislike might be a better description. Then make the chart show color or size to indicate the preferences.