its going to be a uphill experience for you, but as long as the game lets you play, you find enjoyment in it and it does not ruin other peoples experiences. They should have 0 reason to make you unable to play, be it through a lowered ping roof, packet loss limits or by "banned for mistaken lagswitching".
If it does end up being a broken experience for others playing against or with you, then I could see that they would lower the acceptable network limits. But I don't see them banning you, especially since there is no malicious intent, you just want to play. And as you said yourself, I think you've done everything you can with the connection that is available to you. The only option you have at this point is A) Fiber internet arrives to your location or B) Starlink. To improve on what you have and those are not really reasonable expectations to put on someone, both are incredibly expensive when not lucky enough that city development basically gives it to you for free.