Form what I heard if your trade is less than 1 minute you have a chance to be banned. Why don't you go to brokers to chat with them, and ask them this question directly? Then you can clear thing up. There is a thread to introduce many high leverage brokers. https://forums.babypips.com/t/going-offshore-to-escape-the-cftc/
I can ask but the thing is if the main reason is not trusting the brokers, do you really think a broker would straight up say I will ban you if you trade short term trades! I doubt that very much. every broker will say the best about themselves. asking this question to a broker to figure out who is the good broker is the same as interviewing ten people and ask them which one of you is a dishonest person? no one will tell the truth
I can see that the problem is on your side , not on broker side. If you have no trust for all of brokers then no way you will find a broker for you. Why brokers want ban traders without justification and lose all of their customers, and they themselves go bankrupt? The trader who was banned always came to forum to complain, and then only to find it was his own fault, because he violate broker's rule. I have yet to see a broker who behavior like you described. If there was one, it does not exist now, because all its customers left.
100's of 2 - 4 mins holds a few sub 1min ( instant SL losers mainly ) this year via ICMarkets, few lasting more than 10mins ( stuck in losers mainly for them ) and no warning or issues yet
They have ToS where majority of reasons why you can be banned are described. The rest fall into "at their own discretion" category and applied rarely. You can sue your broker for unfair treatment, so read client agreement instead of mulling over broker myths.
It is a kind of grey scheme because you are aiming at getting risk free profit. Basically what you need is one swap free account and one account with positive swap, both are offered by Tickmill and Hotforex, for example, but you can search for others. Building position with 0 currency risk exposure you are receiving swaps. The bigger position the more swap you get.