Can you submit a report ticket for a 100% bought/boosted account?

So one guy i played with 100% bought his account, currently has a 20% winrate 6-24 (30 games) ratio with all feeding scores even with his wins. Has a history of being boosted with the champ katarina even though his main role is ADC. When i played with him in lane, all he did was stood at our tower the entire time from the start and averages 3 times lower CS than the enemy. if enemy has 100~ cs he will have 30. Does riot do anything if you submit a manual report with the evidence of being boosted? For example he has an 80% winrate with katarina with hyper boosted stats. ALSO, he started at D3, and when i checked up on him hes now plat 3 with something like 20-30 lp (continually going down).
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