Tracers and Targeting Matrix interaction

Targeting Matrix: “While attacking, at the end of the Neutralize Results step, you may spend 1 focus result. If you do, after the attack is resolved, the defender gains 1 strain token.”

Can I spend a focus result before all results are cancelled by the tracers as the two effects seem to take place at the same time?

You cannot use Targeting Matrix because dice results are cancelled before the End of Neutralize Results step. Once you find out that the attack hits, you activate Tracers effect to gain locks on the target and you must cancel all remaining dice results. You can activate Targeting Matrix only after that because it occurs at the End of that step, but there are no dice results left.