You won’t get banned for false reports. You will get banned if you are AFKing in your games and people report you for AFKing in your games.
You have options.
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Continue ranking solo and ignore the stacks, which is what you claim that you want to do. Turn off your chat if you have to. The game was designed for you to be able to do this, and you can.
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Join the premades. Is this a big deal to you? If so, your loss.
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Play solo but abide by bracket stacks. No one will false report you and you can maintain your solo queue ambitions.
If you choose to play against the grain then you are fighting your own uphill battle and I don’t expect anyone on your server to have any sympathy for you. You shouldn’t either. You are making your choice. There are several individuals on my server who solo ranked to 14. Some went against the stacks, some didn’t.
Best of luck.